[SOLVED] if(!$variable)

[sgtbash]

???

What does this do?

 

Ive searched high and low over the internet for the purpose of the explanation mark before the variable and not found a thing, can someone help!

 

if(!$variable){

 

 

[obsidian]

Check the PHP Comparison Operators in the manual. With that read, it will make more sense.

 

Basically, an if statement evaluates the clause to true or false. Throwing the '!' on the front practically switches the outcome of the statement. So, in that case, you are checking to see that the $variable evaluates to false. If so, then the statement is executed.

[The Little Guy]

$variable = TRUE;

if(!$variable){

}else{

}

 

In the above example the else would be exicuted because $variable is set to TRUE and the ! means NOT, so it is saying:

if $variable is NOT TRUE do this

[sgtbash]

AHAR!!!!

 

Thanks

 

I figured it was something to do with NOT as i use the if(* != *) function all the time but was unaware you could use it to check it that quickly.

 

Thanks

 

Dan

 

[obsidian]

AHAR!!!!

 

Thanks

 

I figured it was something to do with NOT as i use the if(* != *) function all the time but was unaware you could use it to check it that quickly.

 

Thanks

 

Dan

 

You can use it to invert almost any phrase, too, which can get confusing rather quickly:

<?php
function returnFalse() {
  return FALSE;
}

if (!(returnFalse() !== FALSE)) // Evaluates to TRUE every time
{

}
?>