Why is the value of var_dump(true and false) as boolean(true)?

Question

What I want to understand -

$x = true and false;

var_dump($x);

Answer comes out to be as boolean(true);

But under algebra i have been learning as 1 and 0 is 0

Ran the code in php

Actually, `var_dump(true and false)`, as posed in the title, *is* `false`. That's not the same operation as `$x = true and false`… — deceze, Dec 15 '16 at 08:39

score 6 · Accepted Answer · answered Dec 15 '16 at 08:15

6

and has a lower operator precedence than = so what you are executing is:

($x = true) and false;

So the complete expression - which you don't use the result of - will return false, but $x will be true.

answered Dec 15 '16 at 08:15

jeroen

score 3 · Answer 2 · edited May 23 '17 at 12:00

3

It is because the and operator does not work as you think: 'AND' vs '&&' as operator

Basically, = has higher precedence.

$x = false && true;
var_dump($x);

returns bool(false).

As does

$x = (false and true);

edited May 23 '17 at 12:00

Community

answered Dec 15 '16 at 08:14

Bart Friederichs

2 Answers2