PHP strnatcmp() Function

The strnatcmp() function in-built string function of PHP. It is used to compare string by using a natural algorithm.

Syntax:

Parameter	Description	Required/Optional
string1		required
string2		required

This function strnatcmp():

returns: <0 if str1 is less than str2;
returns : >0 if str1 is greater than str2;
returns: 0 if they are equal.

Note: It is case sensitive.

Example 1

<?php
$str1="2Hello world!";
$str2="10Hello world!";
echo "By Using strnatcmp()Function:".strnatcmp($str1,$str2);
// It returns -1.
?>

Output:

By Using strnatcmp()Function:-1

Example 2

<?php
$str1="10Hello world!";
$str2="2Hello world!";
echo "By Using strnatcmp()Function:".strnatcmp($str1,$str2);
// It returns 1.
?>

Output:

By Using strnatcmp()Function:1

Example 3

<?php
$arr1 = $arr2 = array("PHP12", "PHP10", "PHP2", "PHP1");
echo "Standard string comparisonn";
usort($arr1, "strcmp");
print_r($arr1);
echo ?<br>?;
echo "nNatural order string comparisonn";
usort($arr2, "strnatcmp");
print_r($arr2);
?>

Output:

Standard string comparisonnArray 
( 
[0] => PHP1 
[1] => PHP10 
[2] => PHP12 
[3] => PHP2 
)
nNatural order string comparisonnArray 
(
   [0] => PHP1 
   [1] => PHP2  
   [2] => PHP10 
   [3] => PHP12 	
 )