The usage of == and === in php

Question

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What does “===” mean?

I am confused with the use of those operators in php, I am not quite sure when should I use === and when ==.

for example why/when should I write:

if( $some_method_that_returns_something_or_false() === FALSE) {
      //do stuff
}

and when with ==?

Also, does === means I must return bool FALSE or I can return 0? When it is considered an bad practice to use === or ==?

Also when putting something like this:

 if($some_method_that_returns_true_or_false()) {

 }

is that $some_method_that_returns_true_or_false() == TRUE or some_method_that_returns_true_or_false() === TRUE?

There must be 1000 dupes for this question here. Try using the search at the top right. — karim79, Sep 25 '12 at 10:06

score 3 · Accepted Answer · answered Sep 25 '12 at 10:09

3

=== means exact value, so for true it has to be true, while == checks for the meaning of the value, so true will be also a value of '1' or a whatever String.

answered Sep 25 '12 at 10:09

Mihai Dragoi

46
3

I see, so in essence. If I want it to be strictly bool and not for example some object etc I use ===. – ignite1688846 Sep 25 '12 at 10:20
1

Not a whatever string; `"0" != true` and `"" != true` – Ja͢ck Sep 25 '12 at 10:27

score 1 · Answer 2 · answered Sep 25 '12 at 10:10

1

== is used for checking equallity and === is used for checking the equality as well as type.

And

if($some_method_that_returns_true_or_false()) {

}

is checking for $some_method_that_returns_true_or_false() == TRUE

answered Sep 25 '12 at 10:10

Yogesh Suthar

30,424
18
72
100

The usage of == and === in php

2 Answers2