Javascript Boolean

The Boolean object is an object wrapper for a boolean value.

Syntax

new Boolean([value])

Parameters

value
Optional. The initial value of the Boolean object.

Any object whose value is not undefined or null, including a Boolean object whose value is false, evaluates to true when passed to a conditional statement. For example, the condition in the following if statement evaluates to true:

var x = new Boolean("false");
if (x) {
// this code is executed
}

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean

>>38
Why would you expect a function to behave properly if given improper input? That's a sign of bad programming or bad input, it has nothing to do with a type system. That's like expecting strlen() to give valid results if you pass it a function pointer. Run-time type checking wouldn't fix that; most likely it would throw an exception, and unless you have special error-handling code, it will just end up crashing anyway.