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Hàm strchr() trong PHP

Hướng dẫn cách sử dụng hàm strchr() trong lập trình PHP

Tác dụng của hàm strchr()

The strchr() function find the first occurrence of a string within another string.

This function is case-sensitive. Also, this function is an alias of strstr().

The following table summarizes the technical details of this function.

Return Value: Returns the portion of string, or FALSE if the string to search for is not found.
Changelog: Since PHP 7.3.0, passing an integer as search parameter has been deprecated.
Version: PHP 4+

Syntax

The basic syntax of the strchr() function is given with:

strchr(string, search, before_search);

The following example shows the strchr() function in action.

<?php
// Sample string
$str = "johnclark@mail.com";

// Searching for the substring
echo strchr($str, "@");
?>

Tip: If you simply want to find out if a particular substring occurs within a string or not, use the faster and less memory intensive function strpos() instead.


Parameters

The strchr() function accepts the following parameters.

Parameter Description
string Required. Specifies the string to search.
search Required. Specifies the string to search for.
before_search Optional. If set to true, it returns the part of the string before the first occurrence of the search string. Default value is false which returns all of the string after the first occurrence of the search string (including search string itself).

More Examples

Here're some more examples showing how strchr() function actually works:

The following example returns the part of the string before the first occurrence of @ symbol.

<?php
// Sample string
$str = "johnclark@mail.com";

// Searching for the substring
echo strchr($str, "@", true);
?>

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