str_contains

(PHP 8)

str_containsDetermine if a string contains a given substring

Description

str_contains(string $haystack, string $needle): bool

Performs a case-sensitive check indicating if needle is contained in haystack.

Parameters

haystack

The string to search in.

needle

The substring to search for in the haystack.

Return Values

Returns true if needle is in haystack, false otherwise.

Examples

Example #1 Using the empty string ''

<?php
if (str_contains('abc', '')) {
echo
"Checking the existence of the empty string will always return true";
}
?>

The above example will output:

Checking the existence of the empty string will always return true

Example #2 Showing case-sensitivity

<?php
$string
= 'The lazy fox jumped over the fence';

if (
str_contains($string, 'lazy')) {
echo
"The string 'lazy' was found in the string\n";
}

if (
str_contains($string, 'Lazy')) {
echo
'The string "Lazy" was found in the string';
} else {
echo
'"Lazy" was not found because the case does not match';
}

?>

The above example will output:

The string 'lazy' was found in the string
"Lazy" was not found because the case does not match

Notes

Note: This function is binary-safe.

See Also

  • str_ends_with() - Checks if a string ends with a given substring
  • str_starts_with() - Checks if a string starts with a given substring
  • stripos() - Find the position of the first occurrence of a case-insensitive substring in a string
  • strrpos() - Find the position of the last occurrence of a substring in a string
  • strripos() - Find the position of the last occurrence of a case-insensitive substring in a string
  • strstr() - Find the first occurrence of a string
  • strpbrk() - Search a string for any of a set of characters
  • substr() - Return part of a string
  • preg_match() - Perform a regular expression match

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User Contributed Notes 5 notes

up
20
scm6079
2 years ago
For earlier versions of PHP, you can polyfill the str_contains function using the following snippet:

<?php
// based on original work from the PHP Laravel framework
if (!function_exists('str_contains')) {
    function
str_contains($haystack, $needle) {
        return
$needle !== '' && mb_strpos($haystack, $needle) !== false;
    }
}
?>
up
3
olivertasche+nospam at gmail dot com
3 years ago
The code from "me at daz dot co dot uk" will not work if the word is
- at the start of the string
- at the end of the string
- at the end of a sentence (like "the ox." or "is that an ox?")
- in quotes
- and so on.

You should explode the string by whitespace, punctations, ... and check if the resulting array contains your word OR try to test with a RegEx like this:
(^|[\s\W])+word($|[\s\W])+

Disclaimer: The RegEx may need some tweaks
up
1
juliyvchirkov at gmail dot com
2 years ago
<?php

// Polyfill for PHP 4 - PHP 7, safe to utilize with PHP 8

if (!function_exists('str_contains')) {
    function
str_contains (string $haystack, string $needle)
    {
        return empty(
$needle) || strpos($haystack, $needle) !== false;
    }
}
up
-11
kadenskinner at gmail dot com
3 years ago
<?php

$needle
= '@';
$haystack = 'user@example.com';

if (!
str_contains($haystack, $needle)){
echo
'There is not an @ in haystack';
}else{
echo
'There is an @ in haystack';
}
up
-39
me at daz dot co dot uk
3 years ago
# Watch out for aberrant partial matches

$string = 'The lazy fox jumped over the fence';

if (str_contains($string, 'ox')) {
    echo 'The string "ox" was found in the string because it was a partial match';
} else {
    echo '"ox" was not found';
}
//output: The string "ox" was found in the string because it was a partial match

# use spaces for full word matching

$string = 'The lazy fox jumped over the fence';

if (str_contains($string, ' ox ')) {
    echo 'The string " ox " was found in the string because it was a partial match';
} else {
    echo '" ox " was not found';
}
//output:  " ox " was not found
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