the three equal signs

gizzmo

hello can any one make some sense of this to me please

the "=== " how is it used

for example:

if(someVar === false){

what would someVar equal

}

THanks, Giz

Foo

I think you're referring to the 'equality' tester which is 2 equals signs like this:

This is used in the following manner:

if ( $MyVariable == true ) {
Do Something
}

Now, what this means is that the code within the {} signs will ONLY run if $MyVariable happens to have the value TRUE (1) at that particular time.

The area within the brackets ( ) is the 'test' to see whether we will run this code or not.

What the pair of = signs represent is 'Equal to'. So the line reads:

If MyVariable is equal to 'True', do this.

I've not come across three equals signs being used.

LordShryku

Three equal is a strict equallity check, meaning it checks value and type. eg:

if(1 == 1) // true
if(1 == "1") // true
if(1 === 1) // true
if(1 === "1") // false

The last one fails because it is checking a numeric against a string.
http://www.php.net/manual/en/language.operators.comparison.php

Foo

Thanks, that's interesting.

LordShryku

It comes in real handy when doing things like strpos. 0 can be interpreted as false also, so if your position was the first character, without the strict checking, it wouldn't work. Try it....

$string = "blah";
$pos    = strpos($string, "b");
echo ($pos != false)  ? "Position ".$pos."\n" : "False!!!\n"; // lax checking
echo ($pos !== false) ? "Position ".$pos."\n" : "False!!!\n"; // strict checking