### is Checks if the provided value is of the specified type (doesn't work with literals). Use the `instanceof` operator to check if the provided value is of the specified `type`. ```js const is = (type, val) => val instanceof type; ``` ```js is(Array,[1]); // true is(ArrayBuffer, new ArrayBuffer()); // true is(Map, new Map()); // true is(RegExp, /./g); // true is(Set, new Set()); // true is(WeakMap, new WeakMap()); // true is(WeakSet, new WeakSet()); // true is(String, ''); // false is(String, new String('')); // true is(Number, 1); // false is(Number, new Number(1)); // true is(Boolean, true); // false is(Boolean, new Boolean(true)); // true ```