javascript - How to unnest functions in javaScript

Question

I need some help to understand nested function in javaScript. So, below is a fictional script with nested functions, can somebody help me to understand how to unnest them ?

    function start (){

        document.ontouchmove = function1;

        document.onmouseup = function3 = function2; 

    };


    function function1 (){

        //code

    };


    function function2 (){

        // code

    };


    function function3 (){

        //code

    };

Answer 1

您的代码片段中没有嵌套函数。

不过，您将赋值用作表达式，将其返回值用于“链式”赋值。

解除分配的链接只会相当于

function3 = function2;
document.onmouseup = function3;