JavaScript differentiates between the string primitive, an immutable datatype, and the String object.In order to test the difference between the two, we will initialize a string primitive and a string object.We can use the typeof operator to determine the type of a value. So the battle really comes down to toString() and String() when you want to convert a value to a string. boolean string boolean string number string Method 2:Using JSON.stringify() JSON.stringify() converts the javascript object to string which is needed to send data over web server. Must be an integer between 2 and 36. The toString() method will throw a TypeError exception ("Function.prototype… String Methods and Properties. Javascript Web Development Object Oriented Programming. Except it will throw an error for undefined and null . Code: