Javascript 'new Array' problem

Question

I have to use an array which is statically initialized as:

var my = new Array([30,10],[3,32])

I want to create this array dynamically but it seems it is not possible as it appends quotes and creates like this:

var my = new Array("[30,10],[3,32]")
function(data) {
var my = new Array(data);
}

I have tried replace, substring and any other possible way. Any body have any idea how to do this. This is very urgent.

• user395760: So basically you're asking for eval?
• mcgrailm: you many want to see if you can just have it data come in as json and then treat it as such
• T.J. Crowder: What do you mean by "I want to create this array dynamically"? Also, when you say "... it seems it is not possible as it appends quotes..." What do you mean by "it"? Certainly not the JavaScript interpreter, var my = new Array([30,10], [3,32]); is perfectly valid. It creates an array with two entries, each of which is, in turn, an array with two entries: jsbin.com/abemi4 It also works if the values come from other variables (e.g., rather than literals): jsbin.com/abemi4/2 In your quoted function, what would data contain?
• Felix Kling: Where does this string "[30,10],[3,32]" come from? If you create it, why do you create a string? You can add elements to an array with arr.push().

Answer 1

Try:

var arr = JSON.parse("[[30,10],[3,32]]");

• pimvdb: @T.J. Crowder: Because you can safely convert a String into an Aray this way I guess.
• Buhake Sindi: @T.J. Crowder, I wonder the same thing, I don't see the OP ever talking about JSON.
• T.J. Crowder: @pimvdb: But my impression was that he wasn't using a string. In fact, he seems to be complaining that something is mysteriously turning his arguments into a string, though I can't imagine what. Anyway, the question is pretty unclear, so your guess is as good as mine. :-)
• pimvdb: @T.J. Crowder: Oh I'm sorry, I thought 'dynamically' meant that (instead of hardcoding) a String at runtime is supplied, which has to be converted to an array.
• T.J. Crowder: @pimvdb: Could be! I wouldn't think that (there are lots of things you do "dynamically"), but hey... Unless @Deepak bothers to clarify, like I said, your guess is as good as mine. :-)

Answer 2

Why not create something like this?

var my = [[30,10],[3,32]];

• T.J. Crowder: +1 This would be the preferred notation. But his original, as quoted, should also work (provided nothing's redefined Array), it doesn't take us into the parts of new Array that are...tricky...

Answer 3

you should use JSON.parse or even eval

• gion_13: i know, but for this example it is suitable. you know what type of js you're evaluating