function isSameValueZero( a, b ) {
	return ( a === b ) || ( a !== a && b !== b ); // handles NaNs
}
Tests if two double-precision floating-point numbers are the same value.

## Notes

-   The function implements the SameValueZero Algorithm used by `TypedArray` and `ArrayBuffer` constructors, `Map` and `Set` operations, `String.prototype.includes`, and `Array.prototype.includes` since ES2016.
-   In contrast to the strict equality operator `===`, `NaNs` are considered the same value.

@param {number} a - first input value
@param {number} b - second input value
@returns {boolean} boolean indicating whether two double-precision floating-point numbers are the same value

@example
var bool = isSameValueZero( 3.14, 3.14 );
// returns true

@example
var bool = isSameValueZero( -0.0, -0.0 );
// returns true

@example
var bool = isSameValueZero( -0.0, 0.0 );
// returns true

@example
var bool = isSameValueZero( NaN, NaN );
// returns true