How to pass “this” to window setInterval

Question

Suppose I have a function a:

function a() {
    this.b = 1;
    this.set = setInterval(function() {console.log(this.b);}, 200);
}

So when

Answer 1

In your case, you can simply:

function a() {
    var _this = this;
    this.b = 1;
    this.set = setInterval(function () {
      console.log(_this.b);
    }, 200);
}

Normally, we can also have a helper method Function.prototype.bind to fix the this reference.