How do I access a JavaScript object using another object?

Question

I'm trying to access the properties of easeSegmentNameMap using:

easeSegmentNameMap["EMAIL_ENGAGED"].text

I'm getting undefined, it works if I use:

easeSegmentNameMap["EMAIL_ENGAGED"].name

var easeSegmentNameMap = {
  "EMAIL_ENGAGED": {
    name: "emailEngaged"
  },
  "EMAIL_INACTIVE": {
    name: "emailInactive"
  },
  "LIKELY_TO_THRIVE": {
    name: "likelyToThrive"
  },
  "MOST_VALUABLE_SUBSCRIBERS": {
    name: "mostValuableSubscribers"
  },
  "NEARLY_INACTIVE": {
    name: "nearlyInActive"
  },
  "NEVER_ACTIVATED": {
    name: "neverActivated"
  },
  "QUESTION_MARKS": {
    name: "questionMarks"
  }
};

var text = "name";
alert(easeSegmentNameMap["EMAIL_ENGAGED"].text);

Output:

undefined

What am I doing wrong?

There's no property on the objects with the key "text". There is only a single property, and it has the key "name". — Heretic Monkey, Feb 14 '19 at 17:25

score 1 · Answer 1 · answered Feb 14 '19 at 17:25

1

Try this:

alert(easeSegmentNameMap["EMAIL_ENGAGED"][text]);

text is a variable and has to be interpolated.

answered Feb 14 '19 at 17:25

Bryan Scott

4,337
1
9
12

score 1 · Answer 2 · edited Jun 17 '19 at 11:21

1

You can't access

var text="name";
alert(easeSegmentNameMap["EMAIL_ENGAGED"].text);

the text is still the property, in this case, it's not the variable. If you wanted to access the variable you should access like this:

alert(easeSegmentNameMap["EMAIL_ENGAGED"][text]);

edited Jun 17 '19 at 11:21

LogicalBranch

4,248
4
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answered Feb 14 '19 at 17:26

arielb

367
3
10

score 0 · Answer 3 · edited Jun 17 '19 at 11:21

Just need to use [] bracket notation. whenever you need to access any object property using variable you need to use [] notation.

var easeSegmentNameMap = {
  "EMAIL_ENGAGED": {
    name: "emailEngaged"
  },
  "EMAIL_INACTIVE": {
    name: "emailInactive"
  },
  "LIKELY_TO_THRIVE": {
    name: "likelyToThrive"
  },
  "MOST_VALUABLE_SUBSCRIBERS": {
    name: "mostValuableSubscribers"
  },
  "NEARLY_INACTIVE": {
    name: "nearlyInActive"
  },
  "NEVER_ACTIVATED": {
    name: "neverActivated"
  },
  "QUESTION_MARKS": {
    name: "questionMarks"
  }
};

var text = "name";
console.log(easeSegmentNameMap["EMAIL_ENGAGED"][text]);

How do I access a JavaScript object using another object?

3 Answers3