PHP Conference Nagoya 2025

stristr

(PHP 4, PHP 5, PHP 7, PHP 8)

stristr Versione insensibile alle maiuscole/minuscole di strstr()

Descrizione

stristr(string $haystack, string $needle): string

Restituisce il contenuto di haystack dalla prima occorrenza di needle fino alla fine. needle e haystack sono esaminati senza distinguere tra lettere maiuscole e minuscole.

Se needle non viene trovato, la funzione restituisce false.

Se needle non è una stringa, viene convertito in un intero e si utilizza il valore ordinale del carattere.

Example #1 Esempio di uso di stristr()

<?php
$email
= 'USER@EXAMPLE.com';
echo
stristr($email, 'e');
// outputs ER@EXAMPLE.com
?>

Example #2 Verifica se una stringa esiste o meno

<?php
$string
= 'Hello World!';
if(
stristr($string, 'earth') === FALSE) {
echo
'"earth" not found in string';
}
// outputs: "earth" not found in string
?>

Example #3 Utilizzo di un dato non stringa da cercare

<?php
$string
= 'APPLE';
echo
stristr($string, 97); // 97 = lowercase a
// outputs: APPLE
?>

Nota: Questa funzione è binary-safe (gestisce correttamente i file binari)

Vedere anche strstr(), strrchr(), substr() e ereg().

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User Contributed Notes 5 notes

up
17
dpatton.at.confluence.org
22 years ago
There was a change in PHP 4.2.3 that can cause a warning message
to be generated when using stristr(), even though no message was
generated in older versions of PHP.

The following will generate a warning message in 4.0.6 and 4.2.3:
stristr("haystack", "");
OR
$needle = ""; stristr("haystack", $needle);

This will _not_ generate an "Empty Delimiter" warning message in
4.0.6, but _will_ in 4.2.3:
unset($needle); stristr("haystack", $needle);

Here's a URL that documents what was changed:
http://groups.google.ca/groups?selm=cvshholzgra1031224321%40cvsserver
up
7
giz at gbdesign dot net
17 years ago
Just been caught out by stristr trying to converting the needle from an Int to an ASCII value.

Got round this by casting the value to a string.

<?php
if( !stristr( $file, (string) $myCustomer->getCustomerID() ) ) {
// Permission denied
}
?>
up
3
Techdeck at Techdeck dot org
22 years ago
An example for the stristr() function:

<?php
$a
= "I like php";
if (
stristr("$a", "LikE PhP")) {
print (
"According to \$a, you like PHP.");
}
?>

It will look in $a for "like php" (NOT case sensetive. though, strstr() is case-sensetive).

For the ones of you who uses linux.. It is similiar to the "grep" command.
Actually.. "grep -i".
up
-1
notepad at codewalkers dot com
19 years ago
<?php

function stristr_reverse($haystack, $needle) {
$pos = stripos($haystack, $needle) + strlen($needle);
return
substr($haystack, 0, $pos);
}
$email = 'USER@EXAMPLE.com';
echo
stristr_reverse($email, 'er');
// outputs USER

?>
up
-3
jukka
10 years ago
I think there is a bug in php 5.3 in stristr with uppercase Ä containing other character

http://pastebin.com/5bP6uztY

if you search only with täry it works, but as soon as the word is tärylä it does not. TÄRYL works fine
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