Number.prototype.valueOf()

The valueOf() method returns the wrapped primitive value of a Number object.

numObj.valueOf()

A number representing the primitive value of the specified Number object.

This method is usually called internally by JavaScript and not explicitly in web code.

let numObj = new Number(10)
console.log(typeof numObj)  // object

let num = numObj.valueOf()
console.log(num)            // 10
console.log(typeof num)     // number

• Number.prototype.toSource()