Use String As JSON Selector in Object in Javascript

Question

I have a lot of values I need to extract from a JSON object called results. I have stored the keys I care about in another object myKeys.

How can I use the values from myKeys as the selector in results? Ultimately I want the data in results.array1.array2.key, results.array1.anotherThing.key, etc.

const myKeys = {
    key1: '.array1.array2.key',
    key2: '.array1.anotherThing.key',
    key3: '.array1.somethingElse.array2.key'
}

for (let [key, value] of Object.entries(myKeys)){
    let data = {name: key, results: results[value]}
}

score 2 · Accepted Answer · answered Feb 25 '23 at 21:24

How about splitting each key by . and then iteratively fetching the value? Something like this:

data = {}
for (key in myKeys){
  let innerKeys = myKeys[key].split(".").shift(); // yields array ['array1', 'array2', 'key']
  let result = results
  innerKeys.forEach(key => {
    result = result[key]
  });
  data[key] = result;
}

This updates your local result variable to inner object through the forEach loop, and then in the end just set the data[key] to the innermost result value. The shift() function removes the first empty element. You can omit that if you remove the first period character.

Use String As JSON Selector in Object in Javascript

1 Answers1