You can use Array#map with Array#find.

arr1.map(obj => arr2.find(o => o.id === obj.id) || obj);

Show code snippet

var arr1 = [{
    id: '124',
    name: 'qqq'
}, {
    id: '589',
    name: 'www'
}, {
    id: '45',
    name: 'eee'
}, {
    id: '567',
    name: 'rrr'
}];

var arr2 = [{
    id: '124',
    name: 'ttt'
}, {
    id: '45',
    name: 'yyy'
}];

var res = arr1.map(obj => arr2.find(o => o.id === obj.id) || obj);

console.log(res);

Here, arr2.find(o => o.id === obj.id) will return the element i.e. object from arr2 if the id is found in the arr2. If not, then the same element in arr1 i.e. obj is returned.

Different ways to achieve this.

1. By using Object.assign() method. It returns the modified target object.

const data = [{
    "id": 1,
    "name": "January",
    "abc": "abc",
    "xyz": "xyz"
}, {
    "id": 2,
    "name": "February",
    "abc": "abc",
    "xyz": "xyz"
}];

const target = data.find((obj) => obj.id === 2);

const source = {
  id: 2,
  name: 'New Month',
  abc: 'abc123',
  xyz: 'someValue'
};

Object.assign(target, source);

console.log( data );

2. By using array.map() method which creates a new array populated with the results of calling a provided function on every element in the calling array.

const data = [{"id": 1,"name": "January","abc": "abc","xyz": "xyz"}, {"id": 2,"name": "February","abc": "abc","xyz": "xyz"}];

const modifiedObj = {"id": 2,"name": "New month","abc": "1234abc","xyz": "someVlaue"};

const result = data.map((item) => item.id === modifiedObj.id ? modifiedObj : item);

console.log(result);

You could look for the index and update the array, if found or push the object.

var array = [{ name: 'test1', id: 1, data: { a: 1 } }, { name: 'test2', id: 2, data: { a: 2 } }],
    object = { name: 'test3', id: 3, data: { a: 3 } },
    index = array.findIndex(({ name, id }) => name === object.name && id === object.id);

if (index === -1) {
    array.push(object);
} else {
    array[index] = object;
}

console.log(array);

var index = items.indexOf(3452);

if (index !== -1) {
    items[index] = 1010;
}

Also it is recommend you not use the constructor method to initialize your arrays. Instead, use the literal syntax:

var items = [523, 3452, 334, 31, 5346];

You can also use the ~ operator if you are into terse JavaScript and want to shorten the -1 comparison:

var index = items.indexOf(3452);

if (~index) {
    items[index] = 1010;
}

Sometimes I even like to write a contains function to abstract this check and make it easier to understand what's going on. What's awesome is this works on arrays and strings both:

var contains = function (haystack, needle) {
    return !!~haystack.indexOf(needle);
};

// can be used like so now:
if (contains(items, 3452)) {
    // do something else...
}

Starting with ES6/ES2015 for strings, and proposed for ES2016 for arrays, you can more easily determine if a source contains another value:

if (haystack.includes(needle)) {
    // do your thing
}

Instead of finding the index and filtering you could always use .map to return a new array.

const myObj = { id: 2, new: 1 };
const myArr = [{ id: 1 }, { id: 2 }, { id: 3 }];

const newArr = myArr.map(v => {
    return v.id === myObj.id ? myObj : v;
});

It depends on what you would like to do if the item is not found in the array, as this will only replace.

You can use Array#find.

let arr = [
  {
    "enabled": true,
    "deviceID": "eI2K-6iUvVw:APA",
  },
  {
    "enabled": true,
    "deviceID": "e_Fhn7sWzXE:APA",
  },
  {
    "enabled": true,
    "deviceID": "e65K-6RRvVw:APA",
  },
];

const id = 'eI2K-6iUvVw:APA';

arr.find(v => v.deviceID === id).enabled = false;

console.log(arr);

Just use simple array access and reassign at the index

arr[indexValue] = myNewObject