我可以在不使用`this`的情况下在对象的方法中使用对象的属性吗？

Question

In following code, why I cannot access b without this keyword. I am using nodejs to run the code

var o = {
    a: 0,
    b:0,
    m1: function(){
        return this.a+b; //this doesn't compile
    },
}
console.log(o.m1())

Answer 1

Change this.a + b; to this.a + this.b; . There is no variable b but there is a property of the object with that name

 var o = { a: 1, b: 4, m1: function(){ return this.a + this.b; }, } console.log(o.m1())