The has() method of WeakSet instances returns a boolean indicating whether an object exists in this WeakSet or not.

The Symbol.hasInstance static data property represents the well-known symbol @@hasInstance. The instanceof operator looks up this symbol on its right-hand operand for the method used to determine if the constructor object recognizes an object as its instance.

The endsWith() method of String values determines whether a string ends with the characters of this string, returning true or false as appropriate.

The [@@hasInstance]() method of Function instances specifies the default procedure for determining if a constructor function recognizes an object as one of the constructor's instances. It is called by the instanceof operator.

The Math.fround() static method returns the nearest 32-bit single precision float representation of a number.

The Math.asin() static method returns the inverse sine (in radians) of a number. That is,

The BigInt64Array() constructor creates BigInt64Array objects. The contents are initialized to 0n.

The Uint16Array() constructor creates Uint16Array objects. The contents are initialized to 0.

The BigUint64Array typed array represents an array of 64-bit unsigned integers in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0n. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).

The Boolean object represents a truth value: true or false.