Javascript get array by name of a string

Question

I'm having a total of 5 arrays. Name of the array will be selected by the user, based on the users selection we need to perform actions.

var p1s1 = ['5', '1', '6'];
var p1s2 = ['2', '4', '7'];
var p1s3 = ['9', '5', '2'];
var p1s4 = ['2', '5', '8'];
var p1s5 = ['7', '4', '2'];

when user selects a dropdown it will have value p1s3. So i need to pick this particular array and perform operations over this. Could anyone please suggest in this regard.

Thanks

You can put them inside an object, and refer to them by key. Getting variables dynamically by name is a recipe for disaster, and not possible in JS anyway. — elclanrs, Sep 08 '15 at 12:15
You need to have object which is a collection of `key=>value` pair. In your case key will the the name user selects and value will be the array. I hope this helps... — Rayon, Sep 08 '15 at 12:16
Please search before posting. This has been asked several dozen times before, the ground has been thoroughly covered. — T.J. Crowder, Sep 08 '15 at 12:21

score 5 · Accepted Answer · answered Sep 08 '15 at 12:16

5

Use object instead:

var obj = {
  p1s1: ['5', '1', '6'],
  p1s2: ['2', '4', '7'],
  p1s3: ['9', '5', '2'],
  p1s4: ['2', '5', '8'],
  p1s5: ['7', '4', '2']
}

Then access array this way:

obj[selected_value_from_dropdown]

answered Sep 08 '15 at 12:16

ischenkodv

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obj.p1s3, is also valid – A.T. Sep 08 '15 at 12:19
1

@A.T. yes valid but the value is coming from somewhere else and is a variable so the answer is valid – joyBlanks Sep 08 '15 at 12:20

joyBlanks · Answer 2 · 2015-09-08T12:22:17.380

The best way to tackle the solution is having an object rather than multiple variables call it pickUpArray

var pickUpArray = {
  p1s1 : ['5', '1', '6'],
  p1s2 : ['2', '4', '7'],
  p1s3 : ['9', '5', '2'],
  p1s4 : ['2', '5', '8'],
  p1s5 : ['7', '4', '2']
};

Then in your logic say you have the value as val where val = as string 'p1s5' or 'p1s2' etc, which is being passed from the select dropdown. you can select pickUpArray[val]

If you dont have a choice to change this varables you can call eval(val) where val is as string 'p1s5' or 'p1s2' etc, which is being passed from the select dropdown but highly unadvisable.

Javascript get array by name of a string

2 Answers2