函数在javascript中返回函数

Question

I have an array this.colors = [RED, BLUE, GREEN] , and sometimes I would like to pick one random color from this array. When I doing it by this way, the result is normal:

rand_color = this.colors[Math.floor(Math.random() * this.colors.length)]
javascript: console.log(rand_color)
// => rgb(211, 65,  65)

But when I've wrapped it in the function:

this.pick_random_color = function() {
    return this.colors[Math.floor(Math.random() * this.colors.length)];
}

that function doesn't return random value. Instead, I get this message in the log:

color = this.pick_random_color;
javascript: console.log(color); 
// => this.pick_random_color = function() {
// =>   return this.colors[Math.floor(Math.random() * this.colors.length)];
// => }

What's wrong with the function?

Answer 1

Don't you need parentheses after the call to pick_random_color ?

color = this.pick_random_color();

What you appear to be doing is assigning color to the pick_random_color function, not executing it.

Answer 2

You forgot parens. You have to add () to this.pick_random_colors

Answer 3

That is because this.pick_random_color is a reference to a function. You should execute this function by writing this.pick_random_color() .

But make sure the this keywords refers to the original object