How to compare array and object in Javascript?

Question

I have two json array and object I would like to compare two json and push another object

obj1 = ["user1", "user2"]
obj2 = [
  {
    "userName": "user1", 
    "id": "14" 
  },
  {
    "userName": "user2",
    "id": "9",
  },
  {
    "userName": "user3",
    "id": "3",
  },
  {
    "userName": "user4",
    "id": "1",
  }
]

I would like to get the result as below

[
  {
    "userName": "user1",
    "id": "14"
  },
  {
    "userName": "user2",
    "id": "9",
  }
]

After, I tried to compare two arrays and get a result what I need.

var obj1 = ["user1","user2"]
var obj2 = [
  {
    "userName": "user1",
    "id": "14"
  },
  {
    "userName": "user2",
    "id": "9",
  },
  {
    "userName": "user3",
    "id": "3",
  },
  {
    "userName": "user4",
    "id": "1",
  }
]

var objArray = [];
for (var i = 0; i < obj.length; i++) {
if (obj1[i] === obj2.userName) {
  objArray.push(obj2[i]);
}
return objArray;

Please help me to solve the issue. Thanks in advance

Nina Scholz · Accepted Answer · 2018-10-02 14:53:46Z

5

You could filter by checking the name with Array#includes.

var array1 = ["user1", "user2"],
    array2 = [{ userName: "user1", id: "14" }, { userName: "user2", id: "9", }, { userName: "user3", id: "3", }, { userName: "user4", id: "1", }],
    result = array2.filter(({ userName }) => array1.includes(userName));
  
console.log(result);

edited Oct 2, 2018 at 14:53

answered Oct 2, 2018 at 14:50

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

vipatron · Accepted Answer · 2018-10-02 14:58:52Z

You need two loops:

iterate through obj1[i], and for each index of obj1...
- iterate through obj2[] and test each object to see whether the username property's value equals that of obj[i].

 var obj1 =  ["user1","user2"]
 var obj2 = [
  {  
    "userName": "user1", 
   "id": "14" 
  },
 {

   "userName": "user2",  
    "id": "9",    
 },
 {

    "userName": "user3",    
    "id": "3",
  },
{

    "userName": "user4",    
   "id": "1",
 }] 

function myFunction(){
  var objArray = [];
  for (var i=0; i < obj1.length; i++) {
    for (var userIndex=0; userIndex < obj2.length; userIndex++){
      if (obj1[i] === obj2[userIndex].userName){
       objArray.push( obj2[userIndex] );
      }
    }
  }
  return objArray;
};

console.log(myFunction());

Collectives™ on Stack Overflow

How to compare array and object in Javascript?

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related