check a given object exists in object array with javascript code example

Example 1: javascript check if value exists in array of objects

var arr = [{ id: 1, name: 'JOHN' }, 
  { id: 2, name: 'JENNIE'}, 
  { id: 3, name: 'JENNAH' }];

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

console.log(userExists('JOHN')); // true
console.log(userExists('JUMBO')); // false

Example 2: check if object is present in array javascript

//Use something like this:

function containsObject(obj, list) {
    var i;
    for (i = 0; i < list.length; i++) {
        if (list[i] === obj) {
            return true;
        }
    }

    return false;
}

//In this case, containsObject(car4, carBrands) is true. Remove the carBrands.push(car4); call and it will return false instead. If you later expand to using objects to store these other car objects instead of using arrays, you could use something like this instead:

function containsObject(obj, list) {
    var x;
    for (x in list) {
        if (list.hasOwnProperty(x) && list[x] === obj) {
            return true;
        }
    }

    return false;
}