Ndtyjky

I have two arrays such as,

Array 1:

    deletedValuesfromArray =

     [

        { "property_name": "Property three", "property_type": 4, "property_required": true, "property_origin": 2 }, 

        { "property_name": "rstywrtre", "property_type": 3, "property_required": true, "property_origin": 1 }

     ]

Array 2:

  normalArray =

   [

    { "property_name": "Property one", "property_type": 4, "property_required": true, "property_origin": 1 },

     { "property_name": "Property two", "property_type": 5, "property_required": true, "property_origin": 1 }, 

     { "property_name": "Property three", "property_type": 4, "property_required": true, "property_origin": 2 }, 

     { "property_name": "rstywrtre", "property_type": 3, "property_required": true, "property_origin": 1 }

   ]

I would like to compare both arrays and filter the array to get the new one after removing the deletedValuesfromArray (Array 1).

For which i have tried the following,

let newArray = this.normalArray.filter(function (val) {

  return this.deletedValuesfromArray.indexOf(val) == -1;

});

console.log(newArray);

But it doesn't works..

Expected Output is,

New Array

   [

     { "property_name": "Property one", "property_type": 4, "property_required": true, "property_origin": 1 },

     { "property_name": "Property two", "property_type": 5, "property_required": true, "property_origin": 1 }

   ]

Stackblitz that i have tried

The values also will not be unique always it may have a complete duplicate of any object.

How to compare and remove the deleted values from the normal array and get the newarray?

Your filter predicate doesn't work because you can't just compare an object from normalArray to an object from deletedValuesfromArray:

indexOf() compares searchElement to elements of the Array using
strict equality (the same method used by the === or triple-equals
operator).

-- Array.indexOf()

In other words,

{ "property_name": "Property one", "property_type": 4, "property_required": true, "property_origin": 1 } === { "property_name": "Property one", "property_type": 4, "property_required": true, "property_origin": 1 }

// > false

To make the filter work, you need to implement a comparison function. See How to determine equality for two JavaScript objects? for some ideas.

Using lodash :-

npm install --save lodash





import * as _ from "lodash";



var newArray = _.differenceWith(this.normalArray, this.deletedValuesfromArray, _.isEqual);

console.log("newArray", newArray);

one of simple options here you can use JSON.stringify, which will turn objects into strings and compare them as strings, because 2 objects never equal each other by value since it compares them by reference, make sure that your objects keys order are the same

const deletedValuesfromArray =

     [

        { "property_name": "Property three", "property_type": 4, "property_required": true, "property_origin": 2 }, 

        { "property_name": "rstywrtre", "property_type": 3, "property_required": true, "property_origin": 1 }

     ]



  const normalArray =

   [

    { "property_name": "Property one", "property_type": 4, "property_required": true, "property_origin": 1 },

     { "property_name": "Property two", "property_type": 5, "property_required": true, "property_origin": 1 }, 

     { "property_name": "Property three", "property_type": 4, "property_required": true, "property_origin": 2 }, 

     { "property_name": "rstywrtre", "property_type": 3, "property_required": true, "property_origin": 1 }

   ]



const result = normalArray.filter(obj => !deletedValuesfromArray.find(o => JSON.stringify(o) == JSON.stringify(obj)));



console.log(result);

You can proceed with ES6 operators (filter and some) :

 ngOnInit() {

    let newArray = this.normalArray.filter( (val) => {

      return !this.deletedValuesfromArray.some((newval) => {

       return JSON.stringify(newval) === JSON.stringify(val) // check if two objects are the same

      });

    });

    console.log(newArray);

  }

This might also help you.

function display()

{

  let newArray = this.normalArray.filter(function (val) {

  count = 0;

  var flag = true;

  return this.deletedValuesfromArray.find(function(item, i){

  count++;



     if(val.property_name == item.property_name && val.property_type == item.property_type && val.property_required == item.property_required && val.property_origin == item.property_origin ){

       flag =  false;

     }

     if(count == deletedValuesfromArray.length) {

     return flag;

     }

  });

});
}