find duplicate before pushing new values

Question

I need to know the best method to check if the value is in the array before push it

I have an array :

coordinates: [
     {x: 160, y: 160},
     {x: 192, y: 160},
     {x: 224, y: 160},
     {x: 224, y: 192},
     ];

For each call of my function , I need to check if new coordinates is it before proceed to push.

const payload= {x: 224, y: 190}

//Next function call 

const payload = {x: 224, y: 190}   // need to refuse pushing this value

I tried filter and other JS methods without success.

for example:

coordinates.filter(c => {if(payload !== c){coordinates.push(new)});

This one doesn't work for me .

Does this answer your question? [Object comparison in JavaScript](https://stackoverflow.com/questions/1068834/object-comparison-in-javascript) — huichops, Jun 18 '20 at 20:24
Does this answer your question? [How can I check if the array of objects have duplicate property values?](https://stackoverflow.com/questions/30735465/how-can-i-check-if-the-array-of-objects-have-duplicate-property-values) — harish kumar, Jun 18 '20 at 20:30

score 0 · Answer 1 · edited Jun 19 '20 at 12:05

0

var payload = {x: 224, y: 190};
var coordinates = [
 {x: 160, y: 160},
 {x: 192, y: 160},
 {x: 224, y: 160},
 {x: 224, y: 192},
];

var filtered = coordinates.filter(c => c.x == payload.x &&
c.y == payload.y);
if (filtered.length == 0) filtered.push(payload)

console.log("Filtered:", filtered)

edited Jun 19 '20 at 12:05

wscourge

10,657
14
59
80

answered Jun 18 '20 at 20:31

Jigar Gajjar

183
2
12

score 0 · Answer 2 · answered Jun 18 '20 at 20:35

0

since each coordinate is an object, you'll need to do a deep comparison to check if the object exists in your array already:

const coordinates = [{
  x: 160,
  y: 160
}, {
  x: 192,
  y: 160
}, {
  x: 224,
  y: 160
}, {
  x: 224,
  y: 192
}];
const isInArray = newCoordinate => coordinates.filter(c => newCoordinate.x === c.x && newCoordinate.y === c.y).length > 0;
console.log(isInArray({
  x: 0,
  y: 0
})) // false
console.log(isInArray({
  x: 160,
  y: 160
})) // true

answered Jun 18 '20 at 20:35

Ethan Lipkind

1,136
5
7

if it's duplicate how can I do for delete them from array ? – Sebastian Jun 23 '20 at 18:51
you can use the `true` or `false` value returned from `isInArray` to determine whether to push the next coordinate into the array. – Ethan Lipkind Jun 28 '20 at 01:28

score 0 · Answer 3 · answered Jun 18 '20 at 20:41

I hope this helps

var coordinates= [
     {x: 160, y: 160},
     {x: 192, y: 160},
     {x: 224, y: 160},
     {x: 224, y: 192},
     ];

const payload = {x: 225, y: 193};


for(let prop of coordinates){
 if(prop.x == payload.x || prop.y == payload.y){
  var includes = true;
 } else {
  includes = false;
 }
}

if(includes == false){
 coordinates.push(payload);
}
console.log(coordinates);

score 0 · Answer 4 · answered Jun 18 '20 at 20:41

A simple checker function to check duplicate objects

var coordinates=[
     {x: 160, y: 160},
     {x: 192, y: 160},
     {x: 224, y: 160},
     {x: 224, y: 192},
];

const pushCoordinate=(obj)=>{
 var flag=0;
 coordinates.forEach((elem)=>{
   if(obj.x===elem.x && obj.y===elem.y){
     flag=1;
    }
  });
  if(flag===1){
   return false;
  }else{
   return true;
  }
};

var payload1 = {x: 224, y: 190};
var payload2 = {x:224, y:190};

if(pushCoordinate(payload1)){
 coordinates.push(payload1);
}

if(pushCoordinate(payload2)){
 coordinates.push(payload2);
}

console.log(coordinates);

score 0 · Answer 5 · answered Jun 18 '20 at 21:37

you can simply use filter array method to check x,y values

and if the filtered array has no length then there are no matching values and push payload object

let filteredArr;
let coordinates = [
    {x: 160, y: 160},
    {x: 192, y: 160},
    {x: 224, y: 160},
    {x: 224, y: 192}
    ];
    
// checker fn
const checker = (obj) => filteredArr = coordinates.filter(elm => obj.x == elm.x && obj.y == elm.y);

let payload = {x: 224, y: 190};
checker(payload);

// no matching
if (filteredArr.length === 0) coordinates.push(payload);
console.log(coordinates);

score 0 · Answer 6 · answered Jun 19 '20 at 12:14

You can use some() to check whether coordinates array includes the values of payload object

const coordinates = [
  {x: 160, y: 160},
  {x: 192, y: 160},
  {x: 224, y: 160},
  {x: 224, y: 192},
];

const payload = {x: 224, y: 192};

if(!coordinates.some(({x, y}) => x === payload.x && y === payload.y)) {
  coordinates.push(payload);
}

console.log(coordinates);

find duplicate before pushing new values

6 Answers6