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;
}
}
?>
str_contains
(PHP 8)
str_contains — Determine 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
add a note
User Contributed Notes 6 notes
scm6079 ¶
9 months ago
juliyvchirkov at gmail dot com ¶
5 months 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, $needle) !== false;
}
}
AuxData ¶
1 month ago
Until PHP 8 was released, many-a-programmer were writing our own contain() functions. Mine also handles needles with logical ORs (set to '||').
Here it is.
function contains($haystack, $needle, $offset){
$OR = '||';
$result = false;
$ORpos = strpos($needle, $OR, 0);
if($ORpos !== false){ //ORs exist in the needle string
$needle_arr = explode($OR, $needle);
for($i=0; $i < count($needle_arr); $i++){
$pos = strpos($haystack, trim($needle_arr[$i]), $offset);
if($pos !== false){
$result = true;
break;
}
}
} else {
$pos = strpos($haystack, trim($needle), $offset);
if($pos !== false){
$result = true;
}
}
return($result);
}
Call: contains("Apple Orange Banana", "Apple || Walnut", 0);
Returns: true
olivertasche+nospam at gmail dot com ¶
9 months 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
kadenskinner at gmail dot com ¶
10 months 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';
}
me at daz dot co dot uk ¶
11 months 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
