Use variable name in dynamic way

JavaScript
1

Hi, i cannot make string ‘KOMMUNENUM’ be assigned as a variable in tt2:

var tt2 = 'KOMMUNENUM';

for (i = 0; i < diam.features.length; i++) { 

alert(diam.features[i].properties.tt2);

what i really want as a result is this:

alert(diam.features[i].properties.KOMMUNENUM)

is there a way for tt2 to apply KOMMUNENUM?

appreciate any help

2

Hi,

What is diam and features and properties?

Could you provide a full code snippet?

Hi, i cannot make string ‘KOMMUNENUM’ be assigned as a variable in tt2:

From the code you’ve provided us I see that you have successfully reached what you want, because if you execute console.log(tt2); the output will be like "KOMMUNENUM". Even if you alert(tt2); you will see this:

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3

Hi, thanks for your answer.

I can try to rephrase the question.

typing this alone gives me the wanted results: alert(diam.features[i].properties.KOMMUNENUM)

but I want to be able to do it dynamically through a variable. Meaning instead of typing KOMMUNENUM (which is a property in an object) i want to be able to just type:

alert(diam.features[i].properties.tt2)

where tt2 can be changed by user in an interface to reference any property name in the object.

So the question is:

how can I make tt2 apply KOMMUNENR as a property in an object?

4

Send me your object so I can deeper understand what you mean.

For now, I can only suppose that there is no value like diam.features[i].properties.tt2 in your object ot it is but equals some other output.

Doing this var tt2 = 'KOMMUNENUM'; you are not changing the value of diam.features[i].properties.tt2, instead of it you are creating a new variable which is not related to your object in any way.

Here is a snippet which I hope will help you to understand what are you doing wrong:

var object = {
  "first": "output1",
  "second": "output2",
  "third": {
    "firstOf3": "output13",
    tt2: "some output"
  }
};

console.log(object["third"].tt2); // "some output"

object["third"].tt2 = "KOMMUNENR";

var tt2 = "bla bla bla";

console.log(object["third"].tt2); // "KOMMUNENR"

console.log(tt2); // "bla bla bla"

I’ve used console.log() instead of alert() but it do not make much sense in this particular example.

5

thanks again.

  • tt2 does not exists in the object

  • I’m not trying to add tt2 as a new property to the object

  • I’m not trying change or add a value in the object.

  • The object property i have has several properties (KOMMUNENR, PNR, etc)

  • I want tt2 to reference these based on change, so for example:
    user has a dropbox with 2 variables: KOMMUNENR and PNR, when user selects one of those, it will

then run alert(diam.features[i].properties.tt2) where tt2 is either KOMMUNENR or PNR based on what user picked. So if user picked KOMMUNENR it will run:

alert(diam.features[i].properties.KOMMUNENR)

and if user picked PNR it will run:

alert(diam.features[i].properties.PNR)

6

In your code features[i] does what you want.

The trick is to use bracket notation to get the property instead of dot notation.

7

Thank you very much, this worked 100%.

final result was:

alert(diam.features[i].properties[tt2])

i was using dot notation which was wrong.

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