JavaScript conditional return

Asked Oct 18 '18 at 08:43

Active Oct 18 '18 at 09:10

Viewed 48 times

I'm trying to get a Boolean value from a simple condition like this one :

let object = {name: 'test'};
console.log(1 == 1 && object);

But this console.log doesn't displays Boolean value true, but the entire object { name: 'test' }. Can you explain me why ?

Why do I have to use !!, to return a Boolean value like this ?

console.log(1 == 1 && !!object);

Thanks for help.

edited Oct 18 '18 at 09:10

asked Oct 18 '18 at 08:43

Sparw

what is `object` doing here? – Nina Scholz Oct 18 '18 at 08:45
1

`Why do I have to use !!, to return a Boolean value like this ?` because that's how you "coerce" a variable to a Boolean – Jaromanda X Oct 18 '18 at 08:46
Its just an exemple, I just want to check if the object variable exists – Sparw Oct 18 '18 at 08:46
3

Look up the `&&` operator. If both expressions are truthy, it will resolve to the last expression. – CertainPerformance Oct 18 '18 at 08:46
1

an object is always truthy though ... even `{} == true` – Jaromanda X Oct 18 '18 at 08:46
1

`console.log(object !== undefined)` ? – CertainPerformance Oct 18 '18 at 08:46
Okay thanks for you helps guys – Sparw Oct 18 '18 at 08:47
in `1 == 1 && !!object` the `1 == 1` is redundant – Jaromanda X Oct 18 '18 at 08:47
1

See the duplicate. `x && y` evaluates as either `x` or `y` depending on if `x` is truthy or not. It doesn't coerce to a boolean. – Quentin Oct 18 '18 at 08:48

0 Answers0