Proper way to set a function's default parameter to a boolean?

Question

I\'ve a function read() that takes as a boolean paramater. If false is passed in - read(false) - it shouldn\'t run a block of code. It wo

Answer 1

If you're expecting falsey values, use typeof:

var x = typeof x !== 'undefined' ? x : false;

Otherwise, if you do this:

var x = x || true;

And pass in false, the value of x will be true.