javascript - Javascript 中 consice 方法中的词法 this

Question

下面是我的代码和解释。我有一个类，其成员函数和变量如下。 functionOne & functionTwo 是简洁的方法。

function MyUtils() {
    this.actions = {
        functionOne(param1, param2) {
            console.log('This is first function which is not in action');
        },
        functionTwo(param1, param2) {
            console.log('This is second function calling function three');
            //HOW DO I CALL functionThree HERE?
            // I tried doing - this.functionThree() but not working
        }
    }

    this.functionThree() {
        console.log('This is third function');
    }
}

如果函数二被调用，那么我希望函数三在其中被调用？

Answer 1

你可以不用这个关键字，这在 javascript 中使用了闭包语法:

function MyUtils() {

    function functionThree() {
        console.log('This is third function');
    }

    this.actions = {
        functionOne(param1, param2) {
            console.log('This is first function which is not in action');
        },
        functionTwo(param1, param2) {
            console.log('This is second function calling function three');
            //HOW DO I CALL functionThree HERE?
            // I tried doing - this.functionThree() but not working
            functionThree();

        }
    }


}

这是 repl 的输出:(找到 here)

clear
Native Browser JavaScript

This is second function calling function three
This is third function
=> undefined