javascript - What is the difference between if(!!condition) and if(condition)

Question

I often see code that uses !!condition as opposed to just the regular condition. I.e.:

if(!!value){
    doSomething();
}

versus:

if(value){
    doSomething();
}

What is the funcational difference, if there is one? Is one superior to the other? What, if any, are the conditions for picking to use one versus the other?

Answer 1

Technically nothing. The double bang !! type converts value to a boolean - something the if statement does when it evaluates value anyway.

In the code you have posted, the !! is useless and serves no purpose.