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

stristrstrstr() insensible a mayúsculas y minúsculas


stristr(string $haystack, mixed $needle, bool $before_needle = false): string

Devuelve todo de haystack iniciando desde e incluyendo la primera aparición de needle hasta el final.



El string en donde buscar


Si needle no es una cadena, se convierte a un entero y se aplica como el valor ordinal de un carácter. Este comportamiento está obsoleto a partir de PHP 7.3.0, por lo que su uso está totalmente desaconsejado. Dependiendo del comportamiento previsto, needle deberá ser convertido explícitamente a string, o realizar una llamada explícita a chr().


Si es true, stristr() devuelve la parte del haystack anterior a la primera aparición del needle (excluyendo el needle).

needle y haystack se examinan de una manera insensible a mayúsculas y minúsculas.

Valores devueltos

Devuelve el substring coincidente. Si no se encuentra needle, devuelve false.

Historial de cambios

Versión Descripción
5.3.0 Agregado el parámetro opcional before_needle.
4.3.0 stristr() se hizo seguro a nivel binario.


Ejemplo #1 Ejemplo de stristr()

= '';
stristr($email, 'e'); // salida
echo stristr($email, 'e', true); // A partir de PHP 5.3.0, salida US

Ejemplo #2 Probando si un string se encuentra o no

= 'Hello World!';
stristr($string, 'earth') === FALSE) {
'"earth" not found in string';
// salida: "earth" not found in string

Ejemplo #3 Utilizando un needle no "string"

= 'APPLE';
stristr($string, 97); // 97 = a minúscula
// salida: APPLE


Nota: Esta función es segura binariamente.

Ver también

  • strstr() - Encuentra la primera aparición de un string
  • strrchr() - Encuentra la última aparición de un caracter en un string
  • stripos() - Encuentra la posición de la primera aparición de un substring en un string sin considerar mayúsculas ni minúsculas
  • strpbrk() - Buscar una cadena por cualquiera de los elementos de un conjunto de caracteres
  • preg_match() - Realiza una comparación con una expresión regular

add a note

User Contributed Notes 8 notes

21 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", "");
$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:
giz at gbdesign dot net
16 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.

if( !stristr( $file, (string) $myCustomer->getCustomerID() ) ) {
// Permission denied
Techdeck at Techdeck dot org
21 years ago
An example for the stristr() function:

= "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".
notepad at codewalkers dot com
19 years ago

function stristr_reverse($haystack, $needle) {
$pos = stripos($haystack, $needle) + strlen($needle);
substr($haystack, 0, $pos);
$email = '';
stristr_reverse($email, 'er');
// outputs USER

10 years ago
I think there is a bug in php 5.3 in stristr with uppercase Ä containing other character

if you search only with täry it works, but as soon as the word is tärylä it does not. TÄRYL works fine
tomas dot nesrovnal at yourspirit dot cz
15 years ago
Active item item in menu:

function aim($page) {
stristr($_SERVER['REQUEST_URI'], $page)) {
' class="active"';


<style type="text/css">
.active {color: red;}

print '<a href=""'. aim('hello-world') .'>HW</a>';
art at awilton dot dotcom
18 years ago
handy little bit of code I wrote to take arguments from the command line and parse them for use in my apps.


= implode(" ",$argv); //implode all the settings sent via clie
$e = explode("-",$i); // no lets explode it using our defined seperator '-'

//now lets parse the array and return the parameter name and its setting
// since the input is being sent by the user via the command line
//we will use stristr since we don't care about case sensitivity and
//will convert them as needed later.

while (list($index,$value) = each($e)){

//lets grap the parameter name first using a double reverse string
// to get the begining of the string in the array then reverse it again
// to set it back. we will also "trim" off the "=" sign

$param = rtrim(strrev(stristr(strrev($value),'=')),"=");

//now lets get what the parameter is set to.
// again "trimming" off the = sign

$setting = ltrim(stristr($value,'='),"=");

// now do something with our results.
// let's just echo them out so we can see that everything is working

echo "Array index is ".$index." and value is ".$value."\r\n";
"Parameter is ".$param." and is set to ".$setting."\r\n\r\n";



when run from the CLI this script returns the following.

[root@fedora4 ~]# php a.php -val1=one -val2=two -val3=three

Array index is 0 and value is a.php
Parameter is and is set to

Array index is 1 and value is val1=one
Parameter is val1 and is set to one

Array index is 2 and value is val2=two
Parameter is val2 and is set to two

Array index is 3 and value is val3=three
Parameter is val3 and is set to three

[root@fedora4 ~]#
greg at no_ggmac_reply dot com
13 years ago
Beware the example given here:

if stristr($message,'viagra')
or stristr($message,'cialis')

stristr does not search for words, it finds matching substrings. So, for example, the check for 'cialis' will trigger on 'specialist'
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