What is the difference between "!=" and "" in PHP? Which one to use?

According to the PHP documentation both are comparison operators and serve to compare if one value is different from another.

Example (using the var_dump() function to return the result):

<?php
   var_dump( 7 != 7 ); // FALSE, pois não são diferentes

   var_dump( 7 != 6 ); // TRUE, pois são diferentes

   var_dump( 7 <> 7 ); // FALSE, pois não são diferentes

   var_dump( 7 <> 6 ); // TRUE, pois são diferentes
?>

The usage varies depending on your preference, but the most common is to use != .

You can see more about directly in the PHP documentation here

None, are exact synonyms. It's just different ways of writing. Choose which one you find most comfortable. I see that it is more common to use != to be symmetric with == ("equal"), since != would be the same as say "not equal".

Documentation .