TypedArray.prototype.includes()

includes(searchElement)
includes(searchElement, fromIndex)

var uint8 = new Uint8Array([1,2,3]);
uint8.includes(2);     // true
uint8.includes(4);     // false
uint8.includes(3, 3);  // false

// NaN handling (only true for Float32 and Float64)
new Uint8Array([NaN]).includes(NaN); // false, since the NaN passed to the constructor gets converted to 0
new Float32Array([NaN]).includes(NaN); // true;
new Float64Array([NaN]).includes(NaN); // true;