strnatcmp – PHP String Functions

Syntax :

Description :

It’s an inbuilt function of PHP. strnatcmp() function compares the two strings  using a “natural” algorithm.

Parameter :

[table caption=”” width=”100%” colwidth=”15%|15%|15%|55%” colalign=”left|left|left|left”]
Name, Required /Optional, Value Type, Description

string1, Required, String, First string to compare.

string2, Required, String, Second string to compare.

[/table]

Output :

Return values in this function are:

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

Related articles : strcmp(), strcasecmp(), substr(), stristr(), strncasecmp(), strncmp(), strstr(), natsort(), natcasesort().

strnatcmp() – PHP Functions Example 1 :

<?php
// case-sensitive comparison
echo strnatcmp("Hi from tutorialmines.","hI FROM TUTORIALMINES."); 
?>

Output of above code in the browser is as below:

strnatcmp() – PHP Functions Example 2 : It returns 0, if the two strings are equal. Case of character does matter here.

<?php
echo strnatcmp("Hi from tutorialmines.","Hi from tutorialmines.");
echo "<br/>";
echo strnatcmp("Hi tutorialmines.","hI from Tutorialmines.");
?>

Output of above code in the browser is as below:

strnatcmp () – PHP Functions Example 3 :

<?php
echo "String1 is equal to string2 = ";
echo strnatcmp("Hi from tutorialmines.","Hi from tutorialmines.");
echo "\nString1 is less than string2 = ";
echo strnatcmp("Hi from tutorial.","Hi from tutorialmines.");
echo "\nString1 is greater than string2 = ";
echo strnatcmp("Hi from tutorialmines.","Hi from tutorial.");
?>

Output of above code in the browser is as below:

strnatcmp () – PHP Functions Example 4 : difference between this algorithm and the regular computer string sorting algorithms can be seen below:

<?php
$arr1 = $arr2 = array("var12", "var10", "var2", "var1");
echo "Standard string comparison\n";
usort($arr1, "strcmp");
print_r($arr1);
echo "\nNatural order string comparison\n";
usort($arr2, "strnatcmp");
print_r($arr2);
?>

Output of above code in the browser is as below: