Array Iteration in typescript based on two values

Question

This question might be a simple iteration, but I'm stuck in the logic.

I have an array of data which needs to be iterated based on id and code and remove the data only when the code is not present in the given id's.

Here is the Case Scenarios, From the below data,

There are two different code named "GOOGLE" with different id - Valid Case
There are two different code named "FACEBOOK" with different id - Valid Case
There is a code named "TWITTER" which is not present in another id - INVALID Case.

Here, I wanted to remove this data based on case 3.

 {
  "id" : 378,
  "code" : "TWITTER",
  "comment" : "zeeer"
}

Can someone help me with this scenario?

****Below is the original array data****

 data = [ {
  "id" : 381,
  "code" : "GOOGLE",
  "comment" : "ffff"
}, {
  "id" : 381,
  "code" : "FACEBOOK",
  "comment" : "fff"
}, {
  "id" : 378,
  "code" : "TWITTER",
  "comment" : "zeeer"
}, {
  "id" : 378,
  "code" : "GOOGLE",
  "comment" : "rferer"
}, {
  "id" : 378,
  "code" : "FACEBOOK",
  "comment" : "fefehh"
} ]

I tried something below, but not sure how to proceed after this.

And, I'm using angular 7 and it will be helpful if I get the solution based on typescript.

this.data.forEach((row, index) => {
        let value = row.id;
        if(originalArray.indexOf(value) == -1) {
          console.log(value);
        }
        originalArray.push(row);
     })

This question (or at least, the code you've provided) is not related to Angular, nor Typescript. It's just plain old JavaScript. — Tyler Roper
– Tyler Roper, Commented Jul 19, 2019 at 13:47
Yes, I just given a sample with javascript, not sure how to proceed from here — UI_Dev
– UI_Dev, Commented Jul 19, 2019 at 13:52
Also, your logic just seems a bit unclear, to me at least. Is the logic essentially "Remove any ID+Code pair that appears only once"? — Tyler Roper
– Tyler Roper, Commented Jul 19, 2019 at 13:52
"The logic is to remove any ID+Code pair not matched ", then case 1 and case 2 scenarios also not valid right - (GOOGLE 378 is not matching with GOOGLE 381) — Naga Sai A
– Naga Sai A, Commented Jul 19, 2019 at 14:07

Ghoul Ahmed · Accepted Answer · 2019-07-19 13:57:27Z

1

try this:

 data = [ {
  "id" : 381,
  "code" : "GOOGLE",
  "comment" : "ffff"
}, {
  "id" : 381,
  "code" : "FACEBOOK",
  "comment" : "fff"
}, {
  "id" : 378,
  "code" : "TWITTER",
  "comment" : "zeeer"
}, {
  "id" : 378,
  "code" : "GOOGLE",
  "comment" : "rferer"
}, {
  "id" : 378,
  "code" : "FACEBOOK",
  "comment" : "fefehh"
} ]

var result = data.reduce((unique, o) => {
    if(data.filter(obj => obj.id != o.id && obj.code === o.code).length>=1) {
      unique.push(o);
    }
    return unique;
},[]);

console.log(result);

answered Jul 19, 2019 at 13:57

Ghoul Ahmed

4,8342 gold badges17 silver badges25 bronze badges

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

6 Comments

UI_Dev Over a year ago

Thanks Ghoul :) Using ES6 reduce is a good approach. Kudos :)

UI_Dev Over a year ago

But, if we don't have duplicate, it is giving empty array

Tyler Roper Over a year ago

You said "The logic is to remove any ID+Code pair not matched". What does "matched" mean if not "duplicated"?

Ghoul Ahmed Over a year ago

@UI_Dev, can you explain what do you mean not duplicated !?

Ghoul Ahmed Over a year ago

what data did you use that it is giving empty array ?

|

Tyler Roper · Accepted Answer · 2019-07-19 14:15:30Z

1

Your logic that "Any code + Id pair that is not matched is removed" seems to directly contradict your first two cases, given that those pairs aren't matched - the ID is different.

Regardless, the code below will only keep items that have duplicate code with different id.

const data = [ { "id" : 381, "code" : "GOOGLE", "comment" : "ffff" }, { "id" : 381, "code" : "FACEBOOK", "comment" : "fff" }, { "id" : 378, "code" : "TWITTER", "comment" : "zeeer" }, { "id" : 378, "code" : "GOOGLE", "comment" : "rferer" }, { "id" : 378, "code" : "FACEBOOK", "comment" : "fefehh" } ];
let result = data.filter(({id,code}) => !!data.find(obj => obj.code === code && obj.id !== id));
console.log(result);

Optimally you wouldn't need nested array methods here, and rather a lookup/hashmap to prevent unnecessary iteration, but seeing that you already accepted an answer I'll forego that for now.

answered Jul 19, 2019 at 14:15

Tyler Roper

21.7k6 gold badges35 silver badges58 bronze badges

3 Comments

UI_Dev Over a year ago

I really appreciate your effort. But, If I don't have duplicates, it is throwing empty array. For example, if we have only first two set of data from the given array, it is throwing empty response.

UI_Dev Over a year ago

In the above case, Both are same id, so it should return 2 data

Tyler Roper Over a year ago

"For example, if we have only first two set of data from the given array" - How is that any different from Twitter in the first example? It has the same ID as others but you said to exclude it because "it's not present in another id". "There are two different code named "GOOGLE" with different id" - If you only have the first two sets of data from the given array, as you suggest, then this is not true. Why would it be included?

MoxxiManagarm · Accepted Answer · 2019-07-19 14:05:23Z

With Lodash

const data = [ {
      "id" : 381,
      "code" : "GOOGLE",
      "comment" : "ffff"
    }, {
      "id" : 381,
      "code" : "FACEBOOK",
      "comment" : "fff"
    }, {
      "id" : 378,
      "code" : "TWITTER",
      "comment" : "zeeer"
    }, {
      "id" : 378,
      "code" : "GOOGLE",
      "comment" : "rferer"
    }, {
      "id" : 378,
      "code" : "FACEBOOK",
      "comment" : "fefehh"
    } ];

    const groupedData = _.groupBy(data, 'code'); // import * as _ from 'lodash'

    console.log(data.filter(entry => groupedData[entry.code].length > 1));

Result:

[Object, Object, Object, Object]
0: Object
code: "GOOGLE"
comment: "ffff"
id: 381
__proto__: Object
1: Object
code: "FACEBOOK"
comment: "fff"
id: 381
__proto__: Object
2: Object
code: "GOOGLE"
comment: "rferer"
id: 378
__proto__: Object
3: Object
code: "FACEBOOK"
comment: "fefehh"
id: 378
__proto__: Object

Collectives™ on Stack Overflow

Array Iteration in typescript based on two values

3 Answers 3

6 Comments

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

6 Comments

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related