Question

I want to call a function this way

redBall(this);

but I want to dynamically construct from a string. I tried something like this but it’s not working.

var color = 'red';
color+'Ball'(this);

Answer 1

You could do something like this:

var ballFunctions = {
    redBall: function(obj) {
        alert("Hi, I'm a red ball");
    },
    blueBall: function(obj) {
        alert("Hi, I'm a blue ball");
    }
};

color = "red";
ballFunctions[color + "Ball"](this);
color = "blue";
ballFunctions[color + "Ball"](this);

---

You could also combine this with Jimmy’s answer and do:

function ball(color, obj) {
    ballFunctions[color + "Ball"](obj);

    // Or use the window object if your funcs are in the global namespace like Cameron said
    // window[color + "Ball"](obj);
}

color = "red";
ball(color, this);