pass a variable to handle dot notation in a object

Question

Here is an explanation of what I want. let's say we have an array of objects.

the first console.log works as expected but I can't make the second one work correctly... I want the second console.log to do the same thing as the first one.

How can do this?

     var sentences = [
    { passed: {mean: 10, shadow: 11, write: 12}}
];
        
        let a = 'mean';
        console.log(sentences[0].passed.mean)
        console.log(sentences[0].passed.a);

Thank you guys plus one .... – Sara Ree Aug 07 '19 at 17:35 — Sara Ree, Aug 07 '19 at 17:35

score 3 · Accepted Answer · answered Aug 07 '19 at 17:14

3

console.log(sentences[0].passed[a])

This uses a as a variable.

answered Aug 07 '19 at 17:14

Michael Bianconi

5,072
1
10
25

last question why this doesn't work? `console.log(sentences[0].passed[a]++)` but this one works: `console.log(sentences[0].passed[a]+1)` – Sara Ree Aug 07 '19 at 17:39
Am I missing something? – Sara Ree Aug 07 '19 at 17:40
What's the output of those two statements? – Michael Bianconi Aug 07 '19 at 17:43
please have a look at my questions Edit – Sara Ree Aug 07 '19 at 17:47
got it!............ – Sara Ree Aug 07 '19 at 18:06

score 1 · Answer 2 · answered Aug 07 '19 at 17:16

You can use bracket notation for this:

var sentences = [{
  passed: {
    mean: 10,
    shadow: 11,
    write: 12
  }
}];

let a = 'mean';
console.log(sentences[0].passed.mean)
//Like this:
console.log(sentences[0]['passed'][a]);
//or this:
console.log(sentences[0].passed[a]);

Since a is a variable, you need use bracket notation to get the value from the object's corresponding property (dot-notation won't work in that way)

pass a variable to handle dot notation in a object

2 Answers2