str_contains

(PHP 8)

str_containsDetermine if a string contains a given substring

说明

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

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

参数

haystack

The string to search in.

needle

The substring to search for in the haystack.

返回值

Returns true if needle is in haystack, false otherwise.

范例

示例 #1 Using the empty string ''

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

以上例程会输出:

Checking the existence of the empty string will always return true

示例 #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';
}

?>

以上例程会输出:

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

注释

注意: 此函数可安全用于二进制对象。

参见

  • 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() - 查找字符串首次出现的位置(不区分大小写)
  • strrpos() - 计算指定字符串在目标字符串中最后一次出现的位置
  • strripos() - 计算指定字符串在目标字符串中最后一次出现的位置(不区分大小写)
  • strstr() - 查找字符串的首次出现
  • strpbrk() - 在字符串中查找一组字符的任何一个字符
  • substr() - 返回字符串的子串
  • preg_match() - 执行匹配正则表达式

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User Contributed Notes 7 notes

up
62
scm6079
1 year 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
2
aisunny7 dot xy at gmail dot com
6 months ago
The polyfill that based on original work from the PHP Laravel framework had a different behavior;

when the $needle is `""` or `null`:
php8's will return `true`;
but, laravel'str_contains will return `false`;

when php8.1, null is deprecated, You can use `$needle ?: ""`;
up
3
juliyvchirkov at gmail dot com
1 year 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
1
drupalista dot com dot br at gmail dot com
3 months ago
private function contains(array $needles, string $type, string $haystack = NULL, string $filename = NULL) : bool {
        if (empty($needles)) return FALSE;
        if ($filename)
            $haystack = file_get_contents($filename);

        $now_what = function(string $needle) use ($haystack, $type) : array {
            $has_needle = str_contains($haystack, $needle);
            if ($type === 'any' && $has_needle)
                return ['done' => TRUE, 'return' => TRUE];

            if ($type === 'all' && !$has_needle)
                return ['done' => TRUE, 'return' => FALSE];

            return ['done' => FALSE];
        };

        foreach ($needles as $needle) {
            $check = $now_what($needle);
            if ($check['done'])
                return $check['return'];
        }
        return TRUE;
    }

    function containsAny(array $needles, string $haystack = NULL, string $filename = NULL) : bool {
        return self::contains($needles, 'any', $haystack, $filename);
    }

    function containsAll(array $needles, string $haystack = NULL, string $filename = NULL) : bool {
        return self::contains($needles, 'all', $haystack, $filename);
    }
up
0
olivertasche+nospam at gmail dot com
1 year 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
-4
AuxData
8 months 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
up
-31
kadenskinner at gmail dot com
1 year 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';
}
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