Question

I am trying to have a javascript object tree behave like a php associative array in the following way.

var key1 = 'a';
var key2 = 'b';
var key3 = 'c';

var obj[key1][key2][key3] = 'd';

However, in javascript I believe you need to define each property/object pair individually, forming deeper leaves. Something like:

var obj[key1] = {};
var obj[key1][key2] = {};
...

Is there a way to simplify or shorten this script?

Thanks

Answer 1

I don’t know if there’s a “natural” way to do it, but you could do it like this:

function phpLike(){};
phpLike.prototype.set = function ()
{
    var l = arguments.length;
    if (l<2) return;
    var o = this;
    for (var i=0; i<l-2; i++)
    {
        if (o[arguments[i]] === undefined) o[arguments[i]] = {};
        o = o[arguments[i]];
    }
    o[arguments[l-2]] = arguments[l-1];
}

// Test
var key1 = 'a';
var key2 = 'b';
var key3 = 'c';
var obj = new phpLike();
obj.set(key1, key2, key3, 'd');
alert(obj[key1][key2][key3]);