如何在Javascript中创建变量，并在变量名称中添加一个不断变化的数字？

Question

This code is completely wrong, but I hope it gives you the idea of what I'm going for:

var qarowquestion+obj.returnIntJson;

obj.returnIntJson's value is just an integer. I want to take the value held there, for example: 2043, and add 2043 to the end of qarowquestion. Thus, I would have:

var qarowquestion2043;

Thanks.

Answer 1

var myObj = {};
myObj['qarowquestion' + obj.returnIntJson] = 'some Val';

Try the above. It will take advantage of dynamic javascript and create a qarowquestion2043 property on the myObj object.

Answer 2

TGH's reply was almost what I needed, or it is and I just don't know how to use it.

I changed it so that the part with the number is the value, not the key.

    var myObj = {};
    myObj['qarowquestion'] = "qarowquestion" + obj.returnIntJson;

Now, I can access it with: myObj.qarowwquestion which gives such result: qarowquestion2043

And for a specific example, in my case:

document.getElementById("qarow" + obj.returnIntJson).innerHTML = myObj.qarowquestion;

Answer 3

You cannot create variable, As TGH mentioned you can add your values as a named properties inside an object.

var obj = {};
obj['qarowquestion' + obj.returnIntJson] = 'xxx';

By this way you can give proper namespace also for your objects.

var someNameSpace = {};
someNameSpace['someObject'] = 'someVal';

Hope this will be helpful.

Answer 4

I was going through a relevant SO post on using dynamic variable names in javascript and the accepted answer brings up a very good point (emphasis is mine):

Since ECMA-/Javascript is all about Objects and Contexts (which, are also somekind of Object), every variable is stored in a such called Variable- (or in case of a Function, Activation Object).In the Global scope (= NO function context), you implicitly write those variables into the Global object (= window in a browser).

So for example (again taken from the answer):

function foobar() {
  this.a = 1;
  this.b = 2;

 var name = window['a']; // === undefined as it refers to the global context and is undefined
 alert(name);
 name = this['a']; // === 1
 alert(name); // outputs 1
 alert(a); //outputs 1

//Since we are talking about context here, you could clearly do

this['qarowquestion'+obj.returnIntJson] = "foo";
alert(qarowquestion2043); //outputs foo
}

So in essence, variables can be accessed as objects in specific contexts which can be really helpful.