In PHP 7, a new feature, spaceship operator has been introduced. It is used to compare two expressions. It returns -1, 0 or 1 when first expression is respectively less than, equal to, or greater than second expression.
Example
<?php //integer comparison print( 1 <=> 1);print("<br/>"); print( 1 <=> 2);print("<br/>"); print( 2 <=> 1);print("<br/>"); print("<br/>"); //float comparison print( 1.5 <=> 1.5);print("<br/>"); print( 1.5 <=> 2.5);print("<br/>"); print( 2.5 <=> 1.5);print("<br/>"); print("<br/>"); //string comparison print( "a" <=> "a");print("<br/>"); print( "a" <=> "b");print("<br/>"); print( "b" <=> "a");print("<br/>"); ?>
It produces the following browser output −
0 -1 1 0 -1 1 0 -1 1