How to return true if all values of array are true otherwise return false?

Question

I have a array like this:

var arr = [ true, true, true ];

Now I want to get true, because all keys of array above are true.

another example:

var arr = [ true, false, true ];

Now I need to get false, because there is one false in the array.

How can I do that?

Answer 1

The shortest code to do this would be arr.every(x => x) or arr.every(function(x) {return x}) for ES5 compability.

The every method takes as an argument a function object that returns either true or false, which is used to test each element of the array.

Answer 2

How about:

!arr.includes(false)

It's more readable and has a much better runtime since it stops after the first false. See it in action:

let arr = [ true, true, true ]

console.log(!arr.includes(false))

arr = [ true, false, true ]

console.log(!arr.includes(false))