Decoding of overloading in JavaScript

In JavaScript there is a special data type---function type, and each function of JavaScript is an instance of the type of the functions. Because a function is an object, the function name is actually a pointer to a function object and is not bound to a function.

1<pre name= "code" class= "HTML" >functionsum (num1,num2)2 {3 returnNUM1 +num2;4 }5 6Alert (sum (10,10));// -7 varother =sum;8Alert (Other (10,10));// -9sum =NULL;TenAlert (Other (10,10));// -

The function name as a pointer to a function helps to understand why there is no concept of function overloading in ECMAScript

function sum (NUM1) {return num1 +100function  sum (NUM1) {return num1 +200 ;} Alert (sum);        //  -

Although two functions with the same name are declared, the following function overrides the previous one, which is equivalent to the code below

function sum (NUM1) {return num1 +100function(NUM1) {return num1 +200 ;} Alert (sum);        //  -

When you create a second function, you actually overwrite the first function variable sum of the reference

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