How to compare strings in php (case insensitive)

PHP method of comparing strings without case sensitivity: 1. Use the "strcasecmp(String 1, String 2)" statement; 2. Use the "strnatcasecmp (String 1, String 2)" statement ;3. Use the "strncasecmp(String 1, String 2, length)" statement.

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

Method 1: Use strcasecmp()--Case insensitive

strcasecmp() function compares two strings. The syntax is as follows

strcasecmp(string1,string2)

##ParameterDescriptionRequired. Specifies the first string to compare. Required. Specifies the second string to be compared.

string1
string2

Return value:

• 0 - If the two strings are equal

• >0 - if string1 is greater than string2

Example:

<?php
echo strcasecmp("Hello world!","HELLO WORLD!");
?>

Output:

0

Method 2: Use strnatcasecmp() function--case insensitive

strnatcasecmp The () function uses a "natural" algorithm to compare two strings (case-insensitive).

In natural algorithms, the number 2 is less than the number 10. In computer sorting, 10 is less than 2 because the first number in 10 is less than 2.

Syntax:

strnatcasecmp(string1,string2)

Return value:

• 0 - If the two strings are equal

• >0 - if string1 is greater than string2

Example:

<?php
echo strnatcasecmp("2Hello world!","10Hello WORLD!");
echo "<br>";
echo strnatcasecmp("10Hello world!","2Hello WORLD!");
?>

Output:

-1
1

Method 2: Use strncasecmp() function--case insensitive

strncasecmp() function compares two strings (case-insensitive). The syntax is as follows

strncasecmp(string1,string2,length)

##Parameterstring1string2length Return value:

Description
Required. Specifies the first string to compare.
Required. Specifies the second string to be compared.
Required. Specifies the number of characters per string used for comparison.

0 - If the two strings are equal
>0 - if string1 is greater than string2
##Example:

<?php
echo strncasecmp("Hello world!","hello earth!",6);
?>

Output:

0

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