How to check if a nested property exists?

Question

What is the right way of checking if a nested property exists?

if (openResult.notification) {
      if (openResult.notification.payload) {
        if (openResult.notification.payload.additionalData) {
          if (openResult.notification.payload.additionalData.sensorOpenWarning) {
            // now do sth with openResult.notification.payload.additionalData
          }
        }
      }
    }

Possibly better duplicate target: [Test for existence of nested JavaScript object key](https://stackoverflow.com/q/2631001/4642212). — Sebastian Simon, Mar 14 '18 at 14:28
Welcome to StackOverflow. Please read the help section on how to properly ask questions first. This question is likely to be downvoted / closed, since a simple google search reveals a solution to this problem in the first result (see comment above). Please do some research first. — Jankapunkt, Mar 14 '18 at 14:29

score 0 · Answer 1 · answered Mar 14 '18 at 14:27

0

Use try catch

var obj;

try{
  console.log(obj.one.two.three.four)
}catch(e){
  console.log("obj is undefined")
}

answered Mar 14 '18 at 14:27

Luis felipe De jesus Munoz

7,454
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score 0 · Answer 2 · answered Mar 14 '18 at 14:28

0

You can use this abbreviate form:

const prop2 = ((obj || {}).prop1 || {}).prop2;

Applied to your code would be:

const sensorOpenWarning = ((openResult || {}).notification || {}).payload || {}).additionalData || {}).sensorOpenWarning;

answered Mar 14 '18 at 14:28

Rafa Romero

2,667
5
25
51

How to check if a nested property exists?

2 Answers2