array.includes(element) is giving false only in Angular 8(typescript)

Question

I am having an array as :

const ELEMENT_DATA: any[] =[
      {first:'1001', second:'john', third:'India'}, 
      {first:'1002', second:'Mack', third:'US'}]

Now, I want to check if my array is having an element named "first" or not. simply I want to get the names of elements only or just want to check if my array contains the required element or not in angular 8.

I have tried everything like array.includes(arr) , array.find(arr=>....) , array.some(...) etc. But for everything it's giving false value only. even if the element is present then also it's giving false only.

Answer 1

Now, I want to check if my array is having an element named "first" or not

To check whether any of your array items has a key named first you should use some

 const ELEMENT_DATA = [ {first:'1001', second:'john', third:'India'}, {first:'1002', second:'Mack', third:'US'}]; var result = ELEMENT_DATA.some(e => Object.keys(e).includes('first')); console.log(result);

Answer 2

If i understood correctly, you want to check some element of array includes property "first". I could do it like this

const ELEMENT_DATA = [
      {first:'1001', second:'john', third:'India'}, 
      {first:'1002', second:'Mack', third:'US'}
];
      
var result = ELEMENT_DATA.some(e => e.hasOwnProperty('first'));

console.log(result);