在另一个JS文件中调用具有相同名称的函数

Question

I'm just a bit confused here... If I have one .js file with function like this:

function myMain() {
    var count=0;
    count++;               
    myHelper(count);
    alert(count);
}

function myHelper(count) {
    alert(count);
    count++;
}

Can I still call another method myHelper() on the other .js file? Or is there any other way that I can pass the count variable from one function to another then it will be called to other .js file. Do you have any idea regarding this one? Thanks!

Answer 1

Update: Nowadays you should prefer to use ES6 import / export in a <script> tag with type="module" or via a module bundler like webpack .

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When both script files are included in the same page, they run in the same global JavaScript context, so the two names will overwrite each other. So no, you can not have two functions in different .js files with the same name and access both of them as you've written it.

The simplest solution would be to just rename one of the functions.

A better solution would be for you to write your JavaScript modularly with namespaces, so that each script file adds the minimum possible (preferably 1) objects to the global scope to avoid naming conflicts between separate scripts.

There are a number of ways to do this in JavaScript. The simplest way is to just define a single object in each file:

// In your first script file
var ModuleName = {
    myMain: function () {
        var count=0;
        count++;               
        myHelper(count);
        alert(count);
    },

    myHelper: function (count) {
        alert(count);
        count++;
    }
}

In a later script file, call the function ModuleName.myMain();

A more popular method is to use a self-evaluating function, similar to the following:

(function (window, undefined) {

    // Your code, defining various functions, etc.
    function myMain() { ... }
    function myHelper(count) { ... }

    // More code...

    // List functions you want other scripts to access
    window.ModuleName = {
        myHelper: myHelper,
        myMain: myMain  
    };
})(window)

Answer 2

如果您知道要覆盖方法，则可以先将旧方法存储在变量中，然后通过该变量调用该函数的其他实现。

Answer 3

Yes, you can call myHelper() from any other js file as long as you include both js files in one html or jsp page

you may want to look at this : Can we call the function written in one JavaScript in another JS file?