Funções para String

Veja Também

Para funções de manuseio de string mais poderosas, de uma olhada em funções de expressão regular POSIX e funções de expressão regular compatíveis com Perl .

Índice

  • addcslashes — String entre aspas com barras no estilo C
  • addslashes — Adiciona barras invertidas a uma string
  • bin2hex — Converte um dado binário em representação hexadecimal
  • chop — Sinônimo de rtrim
  • chr — Retorna um caracter específico
  • chunk_split — Divide uma string em pequenos pedaços
  • convert_cyr_string — Converte de um conjunto caracteres cirílico para outro
  • convert_uudecode — Decodifica uma string codificada com uuencode
  • convert_uuencode — Codifica com uuencode uma string
  • count_chars — Retorna informações sobre os caracteres usados numa string
  • crc32 — Calcula polinômio crc32 de uma string
  • crypt — Encriptação unidirecional de string (hashing)
  • echo — Exibe uma ou mais strings
  • explode — Divide uma string em strings
  • fprintf — Escreve uma string formatada para um stream
  • get_html_translation_table — Retorna a tabela de tradução usada por htmlspecialchars e htmlentities
  • hebrev — Converte texto lógico Hebraico para texto visual
  • hebrevc — Converte um texto lógico Hebráico para um texto visual com conversão newline
  • hex2bin — Decodes a hexadecimally encoded binary string
  • html_entity_decode — Converte todas as entidades HTML para os seus caracteres
  • htmlentities — Converte todos os caracteres aplicáveis em entidades html.
  • htmlspecialchars_decode — Converte especiais entidades HTML para caracteres
  • htmlspecialchars — Converte caracteres especiais para a realidade HTML
  • implode — Junta elementos de uma matriz em uma string
  • join — Sinônimo de implode
  • lcfirst — Torna minúsculo o primeiro caractere de uma string
  • levenshtein — Calcula a distância Levenshtein entre duas strings
  • localeconv — Obtém a informação da formatação numérica
  • ltrim — Retira espaços em branco (ou outros caracteres) do início da string
  • md5_file — Calcula hash md5 de um dado arquivo
  • md5 — Calcula o "hash MD5" de uma string
  • metaphone — Calcula a metaphone key de uma string
  • money_format — Formata um número como uma string de moeda
  • nl_langinfo — Retorna informação de linguagem e local
  • nl2br — Insere quebras de linha HTML antes de todas newlines em uma string
  • number_format — Formata um número com os milhares agrupados
  • ord — Retorna o valor ASCII do caractere
  • parse_str — Converte a string em variáveis
  • print — Mostra uma string
  • printf — Mostra uma string formatada
  • quoted_printable_decode — Converte uma string quoted-printable para uma string de 8 bit
  • quoted_printable_encode — Converte uma string de 8 bits em uma string quoted-printable
  • quotemeta — Adiciona uma barra invertida antes dos meta caracteres
  • rtrim — Retira espaço em branco (ou outros caracteres) do final da string
  • setlocale — Define informações locais
  • sha1_file — Calcula a hash sha1 de um arquivo
  • sha1 — Calcula a hash sha1 de uma string
  • similar_text — Calcula a similaridade entre duas strings
  • soundex — Calcula a chave soundex de uma string
  • sprintf — Retorna a string formatada
  • sscanf — Interpreta a entrada de uma string de acordo com um formato
  • str_getcsv — Analisa uma string CSV e retorna os dados em um array
  • str_ireplace — Versão que não diferencia maiúsculas e minúsculas de str_replace.
  • str_pad — Preenche uma string para um certo tamanho com outra string
  • str_repeat — Repete uma string
  • str_replace — Substitui todas as ocorrências da string de procura com a string de substituição
  • str_rot13 — Executa a transformação rot13 em uma string
  • str_shuffle — Mistura uma string aleatoriamente
  • str_split — Converte uma string para um array
  • str_word_count — Retorna informação sobre as palavras usadas em uma string
  • strcasecmp — Comparação de strings sem diferenciar maiúsculas e minúsculas segura para binário
  • strchr — Sinônimo de strstr
  • strcmp — Comparação de string segura para binário
  • strcoll — Comparação de string baseada no local
  • strcspn — Encontra o tamanho do segmento inicial que não contenha a máscara
  • strip_tags — Retira as tags HTML e PHP de uma string
  • stripcslashes — Desfaz o efeito de addcslashes
  • stripos — Encontra a primeira ocorrencia de uma string sem diferenciar maiúsculas e minúsculas
  • stripslashes — Desfaz o efeito de addslashes
  • stristr — strstr sem diferenciar maiúsculas e minúsculas
  • strlen — Retorna o tamanho de uma string
  • strnatcasecmp — Comparação de strings sem diferenciar maiúsculas/minúsculas usando o algoritmo "natural order"
  • strnatcmp — Comparação de strings usando o algoritmo "natural order"
  • strncasecmp — Comparação de string caso-sensitivo de Binário seguro dos primeiros n caracteres
  • strncmp — Comparação de string segura para binário para os primeiros n caracteres
  • strpbrk — Procura na string por um dos caracteres de um conjunto
  • strpos — Encontra a posição da primeira ocorrência de uma string
  • strrchr — Encontra a ultima ocorrência de um caractere em uma string
  • strrev — Reverte uma string
  • strripos — Encontra a posição da última ocorrência de uma string case-insensitive em uma string
  • strrpos — Encontra a posição da última ocorrência de um caractere em uma string
  • strspn — Encontra o comprimento do segmento inicial combinando com a máscara
  • strstr — Encontra a primeira ocorrencia de uma string
  • strtok — Tokeniza uma string
  • strtolower — Converte uma string para minúsculas
  • strtoupper — Converte uma string para maiúsculas
  • strtr — Traduz certos caracteres
  • substr_compare — A comparação binária entre duas strings de um offset até o limite do comprimento de caracteres
  • substr_count — Conta o número de ocorrências de uma substring
  • substr_replace — Substitui o texto dentro de uma parte de uma string
  • substr — Retorna uma parte de uma string
  • trim — Retira espaço no ínicio e final de uma string
  • ucfirst — Converte para maiúscula o primeiro caractere de uma string
  • ucwords — Converte para maiúsculas o primeiro caractere de cada palavra
  • vfprintf — Escreve uma string formatada para um stream
  • vprintf — Mostra uma string formatada
  • vsprintf — Retorna uma string formatada
  • wordwrap — Quebra uma string em um dado número de caracteres
add a note add a note

User Contributed Notes 24 notes

up
2
admin at fivestarbuy dot com
8 years ago
This example lets you parse an unparsed strings variables. Warning: This could cause security leaks if you allow users to pass $variables through this engine. I recommend only using this for your Content Management System.

<?
$mytime=time();
$mydog="My Dog Ate My PHP!";

# Your Parsing String:
$s1 = 'Hyphen Variable Preserving: $mytime, and $mydog';
echo "Before: <br><br>$s1<br><br>";

# Remember, wherever you define this, it will not be defined GLOBAL into the function
# which is why we define it here. Defining it global could lead to security issues.
$vardata=get_defined_vars();

# Parse the string
$s1 = StrParse($s1,$vardata);

echo "After: <br><br>$s1";

function StrParse($str,$vardata) {
# Takes a string, or piece of data, that contains PHP Variables

# For example, unparsed variables like:  Test using time: $mytime
# This example shows $mytime, and not the actual variable value.
# The end result shows the actual variable value of $mytime.

# This is useful for building a content management system,
# and directing your variables into your content data,
# where content is stored in a file or database, unparsed.
# Of course this could slow down page loads, but it's a good way
# to parse data from current variables into your loaded new data
# making it compatible.

# Then the variables are replaced with the actual variable..
$getvarkeys=array_keys($vardata);
$ret=$str;
for ($x=0; $x < count($getvarkeys); $x++) {
    $myvar=$getvarkeys[$x];
    #echo "Variable: " . $myvar . " [" . $vardata[$myvar] . "]<br>";
    $ret=str_replace('$' . $myvar, $vardata[$myvar], $ret);
}
return $ret;

}

?>
up
1
webmaster at cafe-clope dot net
8 years ago
A comprehensive concatenation function, that works with array and strings

<?php
function str_cat() {
 
$args = func_get_args() ;
   
 
// Asserts that every array given as argument is $dim-size.
  // Keys in arrays are stripped off.
  // If no array is found, $dim stays unset.
 
foreach($args as $key => $arg) {
    if(
is_array($arg)) {
      if(!isset(
$dim))
       
$dim = count($arg) ;
      elseif(
$dim != count($arg))
        return
FALSE ;
     
$args[$key] = array_values($arg) ;
    }
  }
       
 
// Concatenation
 
if(isset($dim)) {
   
$result = array() ;
    for(
$i=0;$i<$dim;$i++) {
     
$result[$i] = '' ;
      foreach(
$args as $arg)
       
$result[$i] .= ( is_array($arg) ? $arg[$i] : $arg ) ;
    }
    return
$result ;
  } else {
    return
implode($args) ;
  }
}
?>

A simple example :

<?php
str_cat
(array(1,2,3), '-', array('foo' => 'foo', 'bar' => 'bar', 'noop' => 'noop')) ;
?>

will return :
Array (
  [0] => 1-foo
  [1] => 2-bar
  [2] => 3-noop
)

More usefull :

<?php
$myget
= $_GET ; // retrieving previous $_GET values
$myget['foo'] = 'b a r' ; // changing one value
$myget = str_cat(array_keys($myget), '=', array_map('rawurlencode', array_values($myget))) ;
$querystring = implode(ini_get('arg_separator.output'), $myget)) ;
?>

will return a valid querystring with some values changed.

Note that <?php str_cat('foo', '&', 'bar') ; ?> will return 'foo&bar', while <?php str_cat(array('foo'), '&', 'bar') ; ?> will return array(0 => foo&bar)
up
1
kristin at greenapple dot on dot ca
9 years ago
I really searched for a function that would do this as I've seen it in other languages but I couldn't find it here. This is particularily useful when combined with substr() to take the first part of a string up to a certain point.

strnpos() - Find the nth position of needle in haystack.

<?php

   
function strnpos($haystack, $needle, $occurance, $pos = 0) {
       
        for (
$i = 1; $i <= $occurance; $i++) {
           
$pos = strpos($haystack, $needle, $pos) + 1;
        }
        return
$pos - 1;
       
    }

?>

Example: Give me everything up to the fourth occurance of '/'.

<?php

    $haystack
= "/home/username/www/index.php";
   
$needle = "/";
   
   
$root_dir = substr($haystack, 0, strnpos($haystack, $needle, 4));
   
    echo
$root_dir;
   
?>

Returns: /home/username/www

Use this example with the server variable $_SERVER['SCRIPT_NAME'] as the haystack and you can self-discover a document's root directory for the purposes of locating global files automatically!
up
0
str at maphpia dot com
1 year ago
I was looking for a function to find the common substring in 2 different strings. I tried both the mb_string_intersect and string_intersect functions listed here but didn't work for me. I found the algorithm at http://en.wikibooks.org/wiki/Algorithm_implementation/Strings/Longest_common_substring#PHP so here I post you the function

<?php

/**
* Finds the matching string between 2 strings
*
* @param string $string1
* @param string $string2
* @param number $minChars
*
* @return NULL|string
*
* @link http://en.wikibooks.org/wiki/Algorithm_implementation/Strings/Longest_common_substring#PHP
*/
function string_intersect($string_1, $string_2)
{
   
$string_1_length = strlen($string_1);
   
$string_2_length = strlen($string_2);
   
$return          = "";

    if (
$string_1_length === 0 || $string_2_length === 0) {
       
// No similarities
       
return $return;
    }

   
$longest_common_subsequence = array();

   
// Initialize the CSL array to assume there are no similarities
   
for ($i = 0; $i < $string_1_length; $i++) {
       
$longest_common_subsequence[$i] = array();
        for (
$j = 0; $j < $string_2_length; $j++) {
           
$longest_common_subsequence[$i][$j] = 0;
        }
    }

   
$largest_size = 0;

    for (
$i = 0; $i < $string_1_length; $i++) {
        for (
$j = 0; $j < $string_2_length; $j++) {
           
// Check every combination of characters
           
if ($string_1[$i] === $string_2[$j]) {
               
// These are the same in both strings
               
if ($i === 0 || $j === 0) {
                   
// It's the first character, so it's clearly only 1 character long
                   
$longest_common_subsequence[$i][$j] = 1;
                } else {
                   
// It's one character longer than the string from the previous character
                   
$longest_common_subsequence[$i][$j] = $longest_common_subsequence[$i - 1][$j - 1] + 1;
                }

                if (
$longest_common_subsequence[$i][$j] > $largest_size) {
                   
// Remember this as the largest
                   
$largest_size = $longest_common_subsequence[$i][$j];
                   
// Wipe any previous results
                   
$return       = "";
                   
// And then fall through to remember this new value
               
}

                if (
$longest_common_subsequence[$i][$j] === $largest_size) {
                   
// Remember the largest string(s)
                   
$return = substr($string_1, $i - $largest_size + 1, $largest_size);
                }
            }
           
// Else, $CSL should be set to 0, which it was already initialized to
       
}
    }

   
// Return the list of matches
   
return $return;
}
up
0
navarr at gmail dot com
8 years ago
stripos for PHP4.x

<?php
 
function stripos($haystack,$needle) {
    return
strpos(strtoupper($haystack),strtoupper($needle));
  }
?>
up
0
t0russ at gmail dot com
9 years ago
to kristin at greenaple dot on dot ca:
thanx for sharing.
your function in recursive form proved to be slightly faster and it returns false (as it should) when the character is not found instead of number 0:
<?php
function strnposr($haystack, $needle, $occurance, $pos = 0) {
    return (
$occurance<2)?strpos($haystack, $needle, $pos):strnposr($haystack,$needle,$occurance-1,strpos($haystack, $needle, $pos) + 1);
}
?>
up
0
james dot d dot baker at gmail dot com
9 years ago
<?php
/*
Written By James Baker, May 27th 2005

sentenceCase($string);
    $string: The string to convert to sentence case.

Converts a string into proper sentence case (First letter of each sentance capital, all the others smaller)

Example Usage:
echo sentenceCase("HELLO WORLD!!! THIS IS A CAPITALISED SENTENCE. this isn't.");

Returns:
Hello world!!! This is a capitalised sentence. This isn't.
*/

function sentenceCase($s){
   
$str = strtolower($s);
   
$cap = true;
   
    for(
$x = 0; $x < strlen($str); $x++){
       
$letter = substr($str, $x, 1);
        if(
$letter == "." || $letter == "!" || $letter == "?"){
           
$cap = true;
        }elseif(
$letter != " " && $cap == true){
           
$letter = strtoupper($letter);
           
$cap = false;
        }
       
       
$ret .= $letter;
    }
   
    return
$ret;
}
?>
up
0
Anonymous
9 years ago
In response to hackajar <matt> yahoo <trot> com,

No string-to-array function exists because it is not needed. If you reference a string with an offset like you do with an array, the character at that offset will be return. This is documented in section III.11's "Strings" article under the "String access and modification by character" heading.
up
0
andy a t onesandzeros d o t biz
9 years ago
I use these little doo-dads quite a bit. I just thought I'd share them and maybe save someone a little time. No biggy. :)

// returns true if $str begins with $sub
function beginsWith( $str, $sub ) {
    return ( substr( $str, 0, strlen( $sub ) ) == $sub );
}

// return tru if $str ends with $sub
function endsWith( $str, $sub ) {
    return ( substr( $str, strlen( $str ) - strlen( $sub ) ) == $sub );
}

// trims off x chars from the front of a string
// or the matching string in $off is trimmed off
function trimOffFront( $off, $str ) {
    if( is_numeric( $off ) )
        return substr( $str, $off );
    else
        return substr( $str, strlen( $off ) );
}

// trims off x chars from the end of a string
// or the matching string in $off is trimmed off
function trimOffEnd( $off, $str ) {
    if( is_numeric( $off ) )
        return substr( $str, 0, strlen( $str ) - $off );
    else
        return substr( $str, 0, strlen( $str ) - strlen( $off ) );
}
up
0
[tab!]
9 years ago
//
// string strtrmvistl(  string str, [int maxlen = 64],
//                      [bool right_justify = false],
//                      [string delimter = "<br>\n"])
//
// splits a long string into two chunks (a start and an end chunk)
// of a given maximum length and seperates them by a given delimeter.
// a second chunk can be right-justified within maxlen.
// may be used to 'spread' a string over two lines.
//

function strtrmvistl($str, $maxlen = 64, $right_justify = false, $delimter = "<br>\n") {
    if(($len = strlen($str = chop($str))) > ($maxlen = max($maxlen, 12))) {
        $newstr = substr($str, 0, $maxlen - 3);

        if($len > ($maxlen - 3)) {
            $endlen = min(($len - strlen($newstr)), $maxlen - 3);
            $newstr .= "..." . $delimter;

            if($right_justify)
                $newstr .= str_pad('', $maxlen - $endlen - 3, ' ');

            $newstr .= "..." . substr($str, $len - $endlen);
        }

        return($newstr);
    }

    return($str);
}
up
0
terry dot greenlaw at logicalshift dot com
9 years ago
Here's a simpler "simplest" way to toggle through a set of 1..n colors for web backgrounds:

<?php
$colours
= array('#000000', '#808080', '#A0A0A0', '#FFFFFF');

// Get a colour
$color = next($colors) or $color = reset($colors);
?>

The code doesn't need to know anything about the number of elements being cycled through. That way you won't have to tracking down all the code when changing the number of colors or the color values.
up
-1
administrador(ensaimada)sphoera(punt)com
8 years ago
I've prepared this simple function to obtain a string delimited between tags (not only XML tags!). Anybody needs something like this?.

<?php

function get_string_between($string, $start, $end){
   
$string = " ".$string;
    
$ini = strpos($string,$start);
     if (
$ini == 0) return "";
    
$ini += strlen($start);    
    
$len = strpos($string,$end,$ini) - $ini;
     return
substr($string,$ini,$len);
}

$string = "this [custom] function is useless!!";
echo
get_string_between($string,"[","]");
// must return "custom";
?>
more functions at http://www.sphoera.com
up
-1
Anonymous
8 years ago
to: james dot d dot baker at gmail dot com

PHP has a builtin function  for doing what your function does,

http://php.net/ucfirst
http://php.net/ucwords
up
-1
mike &#34;eyes&#34; moe
7 years ago
Here is a truly random string generator it uses the most common string functions it will work on anywhere.

<?php
   
function random_string($max = 20){
       
$chars = explode(" ", "a b c d e f g h i j k l m n o p q r s t u v w x y z 0 1 2 3 4 5 6 7 8 9");
        for(
$i = 0; $i < $max; $i++){
           
$rnd = array_rand($chars);
           
$rtn .= base64_encode(md5($chars[$rnd]));
        }
        return
substr(str_shuffle(strtolower($rtn)), 0, $max);
    }
?>
up
-1
SteveRusin
8 years ago
The functions below:

function beginsWith( $str, $sub )
function endsWith( $str, $sub )

Are correct, but flawed.  You'd need to use the === operator instead:

function beginsWith( $str, $sub ) {
   return ( substr( $str, 0, strlen( $sub ) ) === $sub );
}
function endsWith( $str, $sub ) {
   return ( substr( $str, strlen( $str ) - strlen( $sub ) ) === $sub );
}

Otherwise, endsWith would return "foobar.0" ends with ".0" as well as "0" or "00" or any amount of zeros because numerically .0 does equal 0.
up
-1
rh at richardhoward dot net
9 years ago
<?php
/**
Utility class: static methods for cleaning & escaping untrusted (i.e.
user-supplied) strings.

Any string can (usually) be thought of as being in one of these 'modes':

pure = what the user actually typed / what you want to see on the page /
       what is actually stored in the DB
gpc  = incoming GET, POST or COOKIE data
sql  = escaped for passing safely to RDBMS via SQL (also, data from DB
       queries and file reads if you have magic_quotes_runtime on--which
       is rare)
html = safe for html display (htmlentities applied)

Always knowing what mode your string is in--using these methods to
convert between modes--will prevent SQL injection and cross-site scripting.

This class refers to its own namespace (so it can work in PHP 4--there is no
self keyword until PHP 5). Do not change the name of the class w/o changing
all the internal references.

Example usage: a POST value that you want to query with:
$username = Str::gpc2sql($_POST['username']);
*/

//This sets SQL escaping to use slashes; for Sybase(/MSSQL)-style escaping
// ( ' --> '' ), set to true.
define('STR_SYBASE', false);

class
Str {
    function
gpc2sql($gpc, $maxLength = false)
    {
        return
Str::pure2sql(Str::gpc2pure($gpc), $maxLength);
    }
    function
gpc2html($gpc, $maxLength = false)
    {
        return
Str::pure2html(Str::gpc2pure($gpc), $maxLength);
    }
    function
gpc2pure($gpc)
    {
        if (
ini_get('magic_quotes_sybase'))
           
$pure = str_replace("''", "'", $gpc);
        else
$pure = get_magic_quotes_gpc() ? stripslashes($gpc) : $gpc;
        return
$pure;
    }
    function
html2pure($html)
    {
        return
html_entity_decode($html);
    }
    function
html2sql($html, $maxLength = false)
    {
        return
Str::pure2sql(Str::html2pure($html), $maxLength);
    }
    function
pure2html($pure, $maxLength = false)
    {
        return
$maxLength ? htmlentities(substr($pure, 0, $maxLength))
                          :
htmlentities($pure);
    }
    function
pure2sql($pure, $maxLength = false)
    {
        if (
$maxLength) $pure = substr($pure, 0, $maxLength);
        return (
STR_SYBASE)
               ?
str_replace("'", "''", $pure)
               :
addslashes($pure);
    }
    function
sql2html($sql, $maxLength = false)
    {
       
$pure = Str::sql2pure($sql);
        if (
$maxLength) $pure = substr($pure, 0, $maxLength);
        return
Str::pure2html($pure);
    }
    function
sql2pure($sql)
    {
        return (
STR_SYBASE)
               ?
str_replace("''", "'", $sql)
               :
stripslashes($sql);
    }
}
?>
up
-2
da (dot) blayde (a t) gmail (dot) com
8 years ago
Sometimes when converting integers to strings, it looks better to have the number spelled out. I wrote this function that converts integers from -999 to 999 into spelled out strings:

function int2str($int=0){
$doOnes=true;
$neg=$int<0?true:false;
$int=abs(round($int));
$str='';
switch(strlen($int)){
  case 1:$int='0'.$int;
  case 2:$int='0'.$int;
  case 3:$int.='';break;
  default:return $int;
}
switch($int{0}){
  case 1:$str.='one-hundred-';break;
  case 2:$str.='two-hundred-';break;
  case 3:$str.='three-hundred-';break;
  case 4:$str.='four-hundred-';break;
  case 5:$str.='five-hundred-';break;
  case 6:$str.='six-hundred-';break;
  case 7:$str.='seven-hundred-';break;
  case 8:$str.='eight-hundred-';break;
  case 9:$str.='nine-hundred-';break;
}
switch($int{1}){
  case 1:
   switch($int{2}){
    case 0:$str.='ten-';break;
    case 1:$str.='eleven-';break;
    case 2:$str.='twelve-';break;
    case 3:$str.='thirteen-';break;
    case 4:$str.='fourteen-';break;
    case 5:$str.='fifteen-';break;
    case 6:$str.='sixteen-';break;
    case 7:$str.='seventeen-';break;
    case 8:$str.='eighteen-';break;
    case 9:$str.='nineteen-';break;
   }
   $doOnes=false;
  break;
  case 2:$str.='twenty-';break;
  case 3:$str.='thirty-';break;
  case 4:$str.='forty-';break;
  case 5:$str.='fifty-';break;
  case 6:$str.='sixty-';break;
  case 7:$str.='seventy-';break;
  case 8:$str.='eighty-';break;
  case 9:$str.='ninety-';break;
}
if($doOnes){
  switch($int{2}){
   case 1:$str.='one-';break;
   case 2:$str.='two-';break;
   case 3:$str.='three-';break;
   case 4:$str.='four-';break;
   case 5:$str.='five-';break;
   case 6:$str.='six-';break;
   case 7:$str.='seven-';break;
   case 8:$str.='eight-';break;
   case 9:$str.='nine-';break;
}}
$str=substr($str,0,-1);
if($neg){
  $str='negative '.$str;
}
if($int=='000'){
  $str='zero';
}
return $str;
}

Hope this helps someone,
-Blayde
up
-1
Stephen Dewey
5 years ago
If you want a function to return all text in a string up to the Nth occurrence of a substring, try the below function.

Works in PHP >= 5.

(Pommef provided another sample function for this purpose below, but I believe it is incorrect.)

<?php

// Returns all of $haystack up to (but excluding) the $n_occurrence occurrence of $needle. Therefore:
//        If there are < $n_occurrence occurrences of $needle in $haystack, the entire string will be returned.
//        If there are >= $n_occurrence occurrences of $needle in $haystack, the returned string will end before the $n_occurrence'th needle.
// This function only makes sense for $n_occurrence >= 1
function nsubstr($needle, $haystack, $n_occurrence)
{
   
// After exploding by $needle, every entry in $arr except (possibly) part of the last entry should have its content returned.
   
$arr = explode($needle,$haystack,$n_occurrence);
   
// Examine last entry in $arr. If it contains $needle, cut out all text except for the text before $needle.
   
$last = count($arr) - 1;
   
$pos_in_last = strpos($arr[$last],$needle);
   
    if (
$pos_in_last !== false)
       
$arr[$last] = substr($arr[$last],0,$pos_in_last);
   
    return
implode($needle,$arr);
}

$string = 'd24jkdslgjldk2424jgklsjg24jskgldjk24';

print
'S:  ' . $string . '<br>';
print
'1: ' . nsubstr('24',$string,1) . '<br>';
print
'2: ' . nsubstr('24',$string,2) . '<br>';
print
'3: ' . nsubstr('24',$string,3) . '<br>';
print
'4: ' . nsubstr('24',$string,4) . '<br>';
print
'5: ' . nsubstr('24',$string,5) . '<br>';
print
'6: ' . nsubstr('24',$string,6) . '<br>';
print
'7: ' . nsubstr('24',$string,7) . '<br>';

/*
// prints:
S: d24jkdslgjldk2424jgklsjg24jskgldjk24
1: d
2: d24jkdslgjldk
3: d24jkdslgjldk24
4: d24jkdslgjldk2424jgklsjg
5: d24jkdslgjldk2424jgklsjg24jskgldjk
6: d24jkdslgjldk2424jgklsjg24jskgldjk24
7: d24jkdslgjldk2424jgklsjg24jskgldjk24
*/

?>

Note that this function can be combined with wordwrap() to accomplish a routine but fairly difficult web design goal, namely, limiting inline HTML text to a certain number of lines. wordwrap() can break your string using <br>, and then you can use this function to only return text up to the N'th <br>.

You will still have to make a conservative guess of the max number of characters per line with wordwrap(), but you can be more precise than if you were simply truncating a multiple-line string with substr().

See example:

<?php

$text
= 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Pellentesque id massa. Duis sollicitudin ipsum vel diam. Aliquam pulvinar sagittis felis. Nullam hendrerit semper elit. Donec convallis mollis risus. Cras blandit mollis turpis. Vivamus facilisis, sapien at tincidunt accumsan, arcu dolor suscipit sem, tristique convallis ante ante id diam. Curabitur mollis, lacus vel gravida accumsan, enim quam condimentum est, vitae rutrum neque magna ac enim.';

$wrapped_text = wordwrap($text,100,'<br>',true);

$three_lines = nsubstr('<br>',$wrapped_text,3);

print
'<br><br>' . $three_lines;

$four_lines = nsubstr('<br>',$wrapped_text,4);

print
'<br><br>' . $four_lines;

/*
prints:

Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Pellentesque id massa. Duis sollicitudin
ipsum vel diam. Aliquam pulvinar sagittis felis. Nullam hendrerit semper elit. Donec convallis
mollis risus. Cras blandit mollis turpis. Vivamus facilisis, sapien at tincidunt accumsan, arcu

Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Pellentesque id massa. Duis sollicitudin
ipsum vel diam. Aliquam pulvinar sagittis felis. Nullam hendrerit semper elit. Donec convallis
mollis risus. Cras blandit mollis turpis. Vivamus facilisis, sapien at tincidunt accumsan, arcu
dolor suscipit sem, tristique convallis ante ante id diam. Curabitur mollis, lacus vel gravida

*/

?>
up
-1
Verdauga
6 years ago
Just a note in regards to bloopletech a few posts down:

The word "and" should not be used when converting numbers to text.  "And" (at least in US English) should only be used to indicate the decimal place.

Example:
1,796,706 => one million, seven hundred ninety-six thousand, seven hundred six.
594,359.34 => five hundred ninety four thousand, three hundred fifty nine and thirty four hundredths
up
-1
php at moechofe dot com
9 years ago
<?php
 
/*
  * str_match
  *
  * return a string with only cacacteres defined in a expression return false if the expression is not valid
  *
  * @param $str string the string
  * @param $match the expression based on the class definition off a PCRE regular expression.
  *   the '[', ']', '\' and '^' at class start need to be escaped.
  *   like : -a-z0-9_@.
  */
 
function str_match( $str, $match )
  {
   
$return = '';
    if(
eregi( '(.*)', $match, $class ) )
    {
     
$match = '['.$regs[1].']';
      for(
$i=0; $i<strlen($str); $i++ )
      if(
ereg( '['.$class[1].']', $str[$i] ) )
     
$return .= $str{$i};
      return
$return;
    }
    else return
false;
  }

 
/*
  * example
  * accept only alphanum caracteres from the GET/POST parameters 'a'
  */

 
if( ! empty($_REQUEST['a']) )
   
$_REQUEST['a'] = str_match( $_REQUEST['a'], 'a-zA-Z0-9' );
  else
   
$_REQUEST['a'] = 'default';
?>
up
-1
m
6 years ago
Regarding the code for the function beginsWith($str, $sub), I found that it has problems when only one character is present after the string searched for. I found that this works better instead:

<?php
function beginsWith($str, $sub) {
    return (
strncmp($str, $sub, strlen($sub)) == 0);
}
?>
up
-1
Pommef
9 years ago
Example: Give me everything up to the fourth occurance of '/'.

<?php

   $haystack
= "/home/username/www/index.php";
  
$needle = "/";
 
   function
strnpos($haystack, $needle, $occurance, $pos = 0) {
       
       
$res = implode($needle,$haystack);
       
       
$res = array_slice($res, $pos$occurance);
       
        return
explode ($needle,$res);
    }
?>
up
-3
Tomek Rychtyk
2 years ago
Get the intersection of two strings using array_intersect

<?php

function string_intersect($string1, $string2)
{
   
$array1 = $array2 = array();

    for(
$i = 0, $j = 0, $s1_len = strlen($string1), $s2_len = strlen($string2);($i < $s1_len) || ($j < $s2_len); $i++, $j++) {
        if(
$i < $s1_len) {
           
$array1[] = $string1[$i];
        }
        if(
$j < $s2_len) {
           
$array2[] = $string2[$j];
        }
    }

    return
implode('', array_intersect($array1, $array2));
}

?>

For more advanced comparison you can use array_uintersect as well.
up
-2
admin at rotarymulundeast dot org
7 years ago
Here's an easier way to find nth...

function nth($numbex){
  if ($numbex%10 == 1 && $numbex%100 != 11) $sth='st';
  elseif ($numbex%10 == 2 && $numbex%100 != 12) $sth='nd';
  elseif ($numbex%10 == 3 && $numbex%100 != 13) $sth='rd';
  else $sth = 'th';
  return $sth;
}

there is is no need to check if the user has entered a non-integer as we may be using this function for expressing variables as well eg. ith value of x , nth root of z ,etc...
To Top