Accesing items with custom keys in object

Question

I have object like this:

{
"first" : "value1",
"second" : "value2"
}

I want to access both values in for cycle. Order of getting values doesn't mind. Usage is for something like value = value + "something". How to acces values which key names I don't know? Of course I can get keys from helping array like:

var keys = ["first", "second"];

And then get them by index and with them get value1 and value2 from my original array. Is there some better way? For some reason foreach doesn't work either.

The array at the top of the question is not JavaScript syntax. — Pointy, Apr 08 '21 at 19:18
You should clarify what you want here. You are showing square brackets `[]`, which means array, but `=>` is not valid within an array and arrays don't have "keys". Objects, on the other hand do have "keys"`. — Scott Marcus, Apr 08 '21 at 19:18
You can use `Object.keys()` to get the keys, loop over that. You can slso use `Object.values()` to get the values, and `Object.entries()` to get both together. — Barmar, Apr 08 '21 at 19:19
Thank you for replies. My solution is understanding the datatype like object. — FoksaK, Apr 08 '21 at 19:22

score 1 · Accepted Answer · answered Apr 08 '21 at 19:22

1

Javascript has a for ... in to loop through keys

for (var key in object) {
   console.log(object[key])
}

answered Apr 08 '21 at 19:22

TSR

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Thank you. Your solution seems profesional. Getting keys in for cycle is really interesting functionality of js. – FoksaK Apr 08 '21 at 19:31

score 1 · Answer 2 · answered Apr 08 '21 at 19:37

To access both values:

const data = {
  "first": "value1",
  "second": "value2"
};

// (1) for-loop

for (const [key, value] of Object.entries(data)) {
  console.log("for-loop:", key, value);
}

// (2) Array.prototype.forEach

Object.entries(data).forEach(([key, value]) => {
  console.log("Array.prototype.forEach:", key, value);
});

score 1 · Answer 3 · answered Apr 08 '21 at 20:06

If you just want the keys and values separately in an array you can do the following:

var data = {
"first" : "value1",
"second" : "value2"
}
var keys = Object.keys(data)
var values = Object.values(values)

Printing them out individually would give you:

console.log(keys)
Output: ["first", "second"]

console.log(values)
Output: ["value1", "value2"]

Accesing items with custom keys in object

3 Answers3