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substr_count> <strtr
Last updated: Fri, 05 Feb 2010

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substr_compare

(PHP 5)

substr_compareBinary safe comparison of 2 strings from an offset, up to length characters

Description

int substr_compare ( string $main_str , string $str , int $offset [, int $length = strlen($main_str) [, bool $case_insensitivity = false ]] )

substr_compare() compares main_str from position offset with str up to length characters.

Parameters

main_str

The main string being compared.

str

The secondary string being compared.

offset

The start position for the comparison. If negative, it starts counting from the end of the string.

length

The length of the comparison.

case_insensitivity

If case_insensitivity is TRUE, comparison is case insensitive.

Return Values

Returns < 0 if main_str from position offset is less than str , > 0 if it is greater than str , and 0 if they are equal. If offset is equal to or greater than the length of main_str or length is set and is less than 1, substr_compare() prints a warning and returns FALSE.

Changelog

Version Description
5.1.0 Added the possibility to use a negative offset .

Examples

Example #1 A substr_compare() example

<?php
echo substr_compare("abcde""bc"12); // 0
echo substr_compare("abcde""de", -22); // 0
echo substr_compare("abcde""bcg"12); // 0
echo substr_compare("abcde""BC"12true); // 0
echo substr_compare("abcde""bc"13); // 1
echo substr_compare("abcde""cd"12); // -1
echo substr_compare("abcde""abc"51); // warning
?>



add a note add a note User Contributed Notes
substr_compare
sleek
23-May-2005 12:07
Modified version of the original posted function. Use this one:

<?php
if (!function_exists('substr_compare')) {
    function
substr_compare($main_str, $str, $offset, $length = NULL, $case_insensitivity = false) {
       
$offset = (int) $offset;

       
// Throw a warning because the offset is invalid
       
if ($offset >= strlen($main_str)) {
           
trigger_error('The start position cannot exceed initial string length.', E_USER_WARNING);
            return
false;
        }

       
// We are comparing the first n-characters of each string, so let's use the PHP function to do it
       
if ($offset == 0 && is_int($length) && $case_insensitivity === true) {
            return
strncasecmp($main_str, $str, $length);
        }

       
// Get the substring that we are comparing
       
if (is_int($length)) {
           
$main_substr = substr($main_str, $offset, $length);
           
$str_substr = substr($str, 0, $length);
        } else {
           
$main_substr = substr($main_str, $offset);
           
$str_substr = $str;
        }

       
// Return a case-insensitive comparison of the two strings
       
if ($case_insensitivity === true) {
            return
strcasecmp($main_substr, $str_substr);
        }

       
// Return a case-sensitive comparison of the two strings
       
return strcmp($main_substr, $str_substr);
    }
}
?>

substr_count> <strtr
Last updated: Fri, 05 Feb 2010
 
 
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