strnatcmp

Definition and usage

strnatcmp() function uses a "natural" algorithm to compare two strings.

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

Note: This function is case sensitive.

Example

Example 1

Use the "natural" algorithm to compare two strings (case sensitive):

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

Try it yourself

Example 2

Differences between natural algorithms (strnatcmp) and conventional computer string sorting algorithms (strcmp):

 <?php
$arr1 = $arr2 = array ( "pic1" , "pic2" , "pic10" , "pic01" , "pic100" , "pic20" , "pic30" , "pic200" ) ;
echo "Standard String Comparison" . "<br>" ;
usort ( $arr1 , "strcmp" ) ;

print_r ( $arr1 ) ;
echo "<br>" ;

echo "Natural Order String Comparison" . "<br>" ;
usort ( $arr2 , "strnatcmp" ) ;

print_r ( $arr2 ) ;
?>

Try it yourself

grammar

 strnatcmp ( string1 , string2 )