You can use the Boolean function to convert a value to a boolean (true or false). Don't confuse it with new Boolean. If you use the new operator, it will create an instance of Boolean.

var x = Boolean(false); // x becomes false
if (x) console.log('hey'); // console doesn't execute.
typeof x; // "boolean"

var y = new Boolean(false); // y becomes a Boolean object.
if (y) console.log('hey'); // it logs 'hey'.
typeof y; // "object"

Learn more in falsy values and truthy values.

You can also use the double not (!!) to do equivalent conversions.