# Egal

Champions: (?)
Details: full proposal
Wiki: here

Exposes the internal `SameValue` algorithm as a function. It introduces the function as `Object.is`.

## ===

Main differences between `===` and `Object.is` are the way `NaN`s and (negative) zeroes are treated. A `NaN` is egal to another `NaN` and negative zeroes are not `egal` from other positive zeroes.

``````Object.is(0, -0); // false
Object.is(NaN, NaN); // true

0 === -0; // true
NaN === NaN; // false``````

## Syntax

There is no new syntax for `Object.is`, obviously.

## Polyfill

This is how you can define `Object.is` in es5:

``````Object.defineProperty(Object, 'is', {
value: function(x, y) {
if (x === y) {
// 0 === -0, but they are not identical
return x !== 0 || 1 / x === 1 / y;
}

// NaN !== NaN, but they are identical.
// NaNs are the only non-reflexive value, i.e., if x !== x,
// then x is a NaN.
// isNaN is broken: it converts its argument to number, so
// isNaN("foo") => true
return x !== x && y !== y;
},
configurable: true,
enumerable: false,
writable: true
});``````