在JavaScript中将元素添加到二维数组的数组中

Question

I had a question I just couldn't find the answer to. Say I have something like the following:

var test = [{"a": "1", "b": "2", "c": "3", "d": "4"}];

Now, say I wanted this test array to have an additional value based on some predetermined condition. I could do this:

if(cond) {
    var test = [{..., "cond": true}];
}
else {
    var test = [{...}];
}

In essence, I want the array key to exist if the condition holds.

I tried the following so far:

test[0]["cond"] = true; // (similar to how php does it, I thought)
test[0].push("cond":true");

But they did not quite work as I intended (or at all). How would I achieve the above? It would avoid a lot of code duplication.

Answer 1

test[0]["cond"] = true;

Should actually work as well as

test[0].cond = true;

Take into consideration that it is not actually a 2D Array, it's an Array of javascript Objects that have different methods than arrays. For instance, javascript Object does not have a push() method.

Answer 2

A Object is not an Array . You have a Object so you can't use push .

You can use the first method:

 var test = [{"a": "1", "b": "2", "c": "3", "d": "4"}];

 // Here you condition
 if (cond === true) { test[0]["cond"] = true; }

See DEMO