array.includes for array of objects code example

Example 1: how to check if an element exists in an array of objects js

var arr = [{ id: 1, username: 'fred' }, 
  { id: 2, username: 'bill'}, 
  { id: 3, username: 'ted' }];

function userExists(username) {
  return arr.some(function(el) {
    return el.username === username;
  }); 
}

console.log(userExists('fred')); // true
console.log(userExists('bred')); // false

Example 2: javascript array contains object

// Works in all browsers
if (array.index(object) !== -1) {
  console.log(`my object is in my array`)
}

// ES7 :
if(array.includes(oject)) {
  console.log(`my object is in my array`)
}

Example 3: check if property has value in array javascript

const magenicVendorExists =  vendors.reduce((accumulator, vendor) => (accumulator||vendor.Name === "Magenic"), false);