Question

I have a mystery object in Javascript – please could someone tell me how to initialise a similar object?

Background: I’ve inherited some code that gets passed a params object from Flash. I want to ‘fake’ the same call, which requires manually constructing the same object. But I can’t work out how to take it, because I don’t know what type of object it is. (It’s not the content that’s the problem: it’s how to initialise the object.)

Please could someone tell me whether the params object following is an array, a list, a hash or something else – or at least how I can work it out for myself, given that there is no typeof in JavaScript?

function doSomething(params) {
    var txt;
    for (p in params) {
       txt = txt + "param:" + p + ", " + params[p] + "\n";
    }
    return txt;
}

Thanks!

Answer 1

This will alert the type of ‘params’.

function doSomething(params) {
    alert("Type of params variable: " + typeof params);
    var txt = '', p;
    for (p in params) {
       txt += "param:" + p + ", " + params[p] + "\n";
    }
    return txt;
}

If you just want to intercept the variable, and pass the param to the original function, try this:

window.originalFunction = doSomething;
window.doSomething = function(param1){
   // do something with param1
   return window.originalFunction(param1);
};

To check whether params is an array or not, try:

alert(params instanceof Array);