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PHP PHP Arrays and Control Structures PHP Conditionals Logical Operators

Kieran Barker
Kieran Barker
15,028 Points
Posted by Kieran Barker
Kieran Barker
15,028 Points

How can a variable (that is not an array) have two values?

I don't understand this...

$var1 = true && false;
$var2 = true and false;

var_dump($var1, $var2);

...which prints out:

bool(false)
bool(true)

To me, these lines read:

"I am putting the value 'true' AND the value 'false' inside the variable called 'var1'"

Surely that's impossible? That would be like trying to do this in JavaScript:

var number = 5 && 10;

Isn't that invalid!? Please explain!

1 Answer

João Rosa
João Rosa
2,629 Points

Well, the variable doesn't store two values - it stores the result between the operation (TRUE && FALSE). The results are different because of precedence - "&&" has a greater precedence than "and" - Check PHP Documentation on precedence

So, in the first statement, it acts like ($var1 = (true && false)) - which returns false, cause nothing can be true and false at the same time.

In the second statement, it acts like (($var2 = true) and false) - which returns true, cause it ignores the false part.

Hope I was clear on the explanation.

Kieran Barker
Kieran Barker
15,028 Points
Kieran Barker
Kieran Barker
15,028 Points

Thank you! I think I understand. I didn’t know that could store the result of an operation like that within a variable.