How to intercept php string

PHP string interception function

substr function

Description : Implement interception of string

Syntax:

string substr(string $string,int $start [, int $length ])

Description: If length is omitted, the string from start to the end of the character is returned; if start or length is a negative number, it is reciprocal.

$str = 'javascript';
echo substr($str,0,4);
//结果是 java
echo substr($str,4);
echo substr($str,-2);//得到pt

The other one is more special, if the length is a negative number then

$str = 'javascript';
echo substr($str,-5,-2);//得cri 即倒数第五开始到倒数第二的前一位

strstr function

Description: Will search for the first occurrence of a string in another string, case-sensitive

Syntax:

string strstr(string $haystack, mixed $needle)

Description: The function returns the rest of the string

Example:

<?php
    $str1 = "abcdef";
    $str2 = "cd";
    $str3 = strstr($str1,$str2);
    echo $str3;

The output result is cdef

stristr function

Description: Search characters The position of the first occurrence of a string in another string, but not case-sensitive

Syntax:

string stristr(string $haystack, mixed needle)

Related recommendations: "PHP Tutorial"

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