Javascript method doesn't see object variable

Question

var Shape = function(type)
{
    this.type = type;

    addEventListener("resize", this.align);
}

Shape.prototype.align = function()
{
    alert(this.type);
}

.

var variable = new Shape('rectangle');

When I resized, I want alert rectangle but it alerts undefined

Answer 1

you need to pass the scope to use this in the resize event.

var Shape = function(type) {
  this.type = type;
  addEventListener("resize", this.align.bind(this));
}

Shape.prototype.align = function() {
  alert(this.type);
}


var variable = new Shape('rectangle');