I have a object array and would like to get key and value by iterating though it, however I only get 0, 1 as index. anyone know why?

const vairable = [{key1: "value1"}, {key2: "value2"}]
Object.keys(vairable).forEach((i: any) => {
    console.log(i); # get 0 and 1, I would like to have key1, key2
});

I have a object array and would like to get key and value by iterating though it, however I only get 0, 1 as index. anyone know why?

const vairable = [{key1: "value1"}, {key2: "value2"}]
Object.keys(vairable).forEach((i: any) => {
    console.log(i); # get 0 and 1, I would like to have key1, key2
});

• javascript
• typescript
• typescript2.0

• What is keySelectors? You have an array of non-uniform objects in vairable. If you want the keys and values of each object, first iterate vairable, then use Object.entries() to iterate the properties of each object – Phil Commented Apr 14, 2020 at 3:33
• @Phil Surprisingly Object.entries is not available in typescript it seems – Isaac Commented Apr 14, 2020 at 3:41
• 1 @Isaac depends on your language level config. See stackoverflow./questions/39741428/… – Phil Commented Apr 14, 2020 at 3:42

4 Answers 4

Object.keys gives the indices of the array itself, not the objects in the values. Iterate over the values and explore them:

const variable = [{key1: "value1"}, {key2: "value2"}];

for (const value of variable) {
    const firstKey = Object.keys(value)[0];
    console.log(firstKey);
}

Please try like this.

const vairable = [{key1: "value1"}, {key2: "value2"}]
vairable.forEach(item =>{
    for (const [key, value] of Object.entries(item)){
       console.log(key , value)
    }
})

it will output :

key1 value1
key2 value2

How about this: Loop through array:

const vairable = [{key1: "value1"}, {key2: "value2"}]
for(let e of vairable) {
  console.log(Object.keys(e))
}

The Object.keys method work on the Object not on the Arrays. If you want a loop through an Object, Then it will work fine like below,

const keys = {key1: "value1", key2: "value2"};

Object.keys(keys).forEach((key) => {
  console.log(key);
});