How to compare two array object but any one of the array object does not having key pair

Question

Compare two objects if any one of the object not having key pair.

    var itemA= [{"name": "saran", "address":"chennai"},
                       {"name": "elango", "address":"chennai"},
                       {"name": "kala", "address": "chennai"}];

    var itemB= [{"name": "saran", "address":"chennai"},
                       {"name": "elango", "address":"chennai"}];

I wrote following code to compare two objects,

  function compareJSON(itemA, itemB) {        
      for(var prop in itemA) {
          if(itemB.hasOwnProperty(prop)) {
              switch(typeof(itemA[prop])) {
                 case "object":
                    compareJSON(itemA[prop], itemB[prop]);
                       break;
                         default:
                             if(itemA[prop] !== itemB[prop]) {
                             }
                         break;
                }
          }
     }

}

Here i have two object i need to compare above two object. I used to for loop for compare two object with hasOwnProperty() method. the prop is having itemA of object it's checked with itemB object if it's different i took itemA object.

Here problem is not able compare itemA 3rd value not able to compare because in itemB does not have a 3rd element.

We can't help you with that code if you don't include `compareJSON`. — T.J. Crowder, Feb 26 '18 at 11:23
Note that (as the syntax highlighting is telling you), the first code block has a syntax error. (It may be as simple as a missing `"` after `name` on the third line.) — T.J. Crowder, Feb 26 '18 at 11:24
https://stackoverflow.com/questions/201183/how-to-determine-equality-for-two-javascript-objects — Chris Satchell, Feb 26 '18 at 11:24
If any of the object comes difference, I need to picked out that object and i have to bold that object in my project — , Feb 26 '18 at 11:25

score 0 · Answer 1 · answered Feb 26 '18 at 11:29

Check this out.

If not equal, you can write your custom modifications/logic.

var itemA= [{"name": "saran", "address":"chennai"},
                       {"name": "elango", "address":"chennai"},
                       {"name": "kala", "address": "chennai"}];

var itemB= [{"name": "saran", "address":"chennai"},
                       {"name": "elango", "address":"chennai"}]; 

let keysA = Object.keys(itemA);
let keysB = Object.keys(itemB);

if(keysA.length === keysB.length) {
 let flag = true;
 keysA.map( a => {
  if(!keysB.includes(a)) {
   flag = false;
  }
  })
  
  flag ? alert('Equal') : alert('Not equal');
} else {
 alert('Not equal');
}

Arman Charan · Answer 2 · 2018-02-26T11:39:22.947

Array.prototype.reduce(), JSON.stringify() and Array.prototype.includes() can be combined to find the differences between Arrays A and B.

// A.
const A = [
  {name: "saran", address:"chennai"},
  {name: "elango", address:"chennai"},
  {name: "kala", address: "chennai"}
 ]

// B.
const B = [
  {name: "saran", address:"chennai"},
  {name: "elango", address:"chennai"}
]

// Differences.
const differences = A.reduce((differences, object) => (!JSON.stringify(B).includes(JSON.stringify(object)) && [...differences, object] || differences), [])

// Log.
console.log(differences)

How to compare two array object but any one of the array object does not having key pair

2 Answers2