Summary of usage of several commonly used PHP string comparison functions

This article mainly introduces the commonly used string comparison functions in PHP. Examples summarize commonly used functions such as substr_compare, strncasecmp, strncmp, strcoll, etc. , has certain reference value, friends in need can refer to it

substr_compare() function compares two strings from the specified starting length, the function returns:

0 - If the two strings are equal, <0 - If string1 (from the starting position) is less than string2, >0 - If string1 (from the starting position) is greater than string2.

Syntax: substr_compare( string1, string2, startpos, length, case), the code is as follows:

$str1="hello world";          //定义字符串1 
$str2="hello world";          //定义字符串2 
$result=substr_compare($str1,$str2,1,10);      //执行比较操作 
echo $result;           //输出结果，1

strnatcasecmp() function uses a "natural" algorithm to compare two strings , In the natural algorithm, the number "2" is less than the number "10", in the computer sorting, "2" is greater than "10", this is because "2" is greater than the first number of "10", the code is as follows :

$str1="hello world";          //定义字符串1 
$str2="hello world";          //定义字符串2 
$result=strnatcasecmp($str1,$str2);       //执行比较操作 
echo $result;           //输出结果，0

strncasecmp() function compares two strings. The function returns:

0 - If the two strings are equal, <0 - If string1 is less than string2, >0 - If string1 is greater than string2.

Syntax: strncasecmp(string1,string2,length), the code is as follows:

$str1="hello world";          //定义字符串1 
$str2="hello world";          //定义字符串2 
$result=strncasemp($str1,$str2,7);       //执行比较操作 
echo $result;           //输出结果，0

strncmp() function compares two strings , the function returns:

0 - if the two strings are equal, <0 - if string1 is less than string2, >0 - if string1 is greater than string2.

Syntax: strncmp(string1, string2, length), the code is as follows:

$str1="hello world";          //定义字符串1 
$str2="hello world";          //定义字符串2 
$result=strncmp($str1,$str2,7);        //执行比较操作 
echo $result;           //输出结果，1

strcoll() function compares two strings , the function returns:

0 - If two characters String equality, <0 - if string1 is less than string2, >0 - if string1 is greater than string2.

The comparison of strings will change according to local settings, aa.

Syntax: strcoll(string1,string2), the code is as follows:

$str1="hello world";          //定义字符串1 
$str2="hello world";          //定义字符串2 
$result=strcoll($str1,$str2);        //执行比较操作 
echo $result;           //输出结果，1

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