Retrive certains keys from an Object

Question

I have this code here.

const find = require('find-process');

find('name', 'TIDAL.exe')
  .then(function (list) {
    console.log(list)
  }, function (err) {
    console.log(err.stack || err);
});

which returns this here

[
  {
    pid: 7752,
    ppid: 9280,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 500,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 1100,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 6424,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 13692,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 3160,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  }
]

I need to extract the "pid" values and store them in an array but I'm stuck on how I should do it. I've looked around and tried some things out but I just can't get it to work.

What did you try? In ES6 you can use something like `let result = array.map(a => a.pid);` — Kurt Van den Branden, Dec 26 '20 at 11:15

Alan Omar · Answer 1 · 2020-12-26T11:04:34.840

2

let data=[{pid:9280,bin:"...",name:"TIDAL.exe",cmd:"..."},{pid:500,ppid:7752,bin:"...",name:"TIDAL.exe",cmd:"..."},{pid:1100,ppid:7752,bin:"...",name:"TIDAL.exe",cmd:"..."},{pid:6424,ppid:7752,bin:"...",name:"TIDAL.exe",cmd:"..."},{pid:13692,ppid:7752,bin:"...",name:"TIDAL.exe",cmd:"..."},{pid:3160,ppid:7752,bin:"...",name:"TIDAL.exe",cmd:"..."}];

let result = data.map(e => e.pid)

console.log(result)

edited Dec 26 '20 at 11:04

answered Dec 26 '20 at 11:00

Alan Omar

4,023
1
9
20

Adding a little bit of description would be helpful for the OP – Sudhanshu Kumar Dec 26 '20 at 11:04

Sudhanshu Kumar · Accepted Answer · 2020-12-26T11:12:06.097

0

You can use map function for getting the array of PID's

var data = [{
    pid: 9280,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 500,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 1100,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 6424,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 13692,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  },
  {
    pid: 3160,
    ppid: 7752,
    bin: '...',
    name: 'TIDAL.exe',
    cmd: '...'
  }
];

let pids = data.map(item => item.pid);
console.log(pids);

It basically returns a new array with the filter that you've applied, Here I return pid of each item and map them into an array.

So your code should be

    const find = require('find-process');

    find('name', 'TIDAL.exe')
      .then(function (list) {
        let pids = list.map(item => item.pid);
        console.log(pids);
      }, function (err) {
        console.log(err.stack || err);
    });

Learn more on Array.prototype.map() here

edited Dec 26 '20 at 11:12

answered Dec 26 '20 at 11:00

Sudhanshu Kumar

1,926
1
9
21

store the result of the map in array don't just log it. – Alan Omar Dec 26 '20 at 11:06
Btw any important reason behind that? – Sudhanshu Kumar Dec 26 '20 at 11:08
2

yes keep make it a habit to write a clean code. – Alan Omar Dec 26 '20 at 11:09
How would I convert it to an array at the start? It's outputting the data to the console but I need to convert the object into an array and then do the map thing. – dethm0r Dec 26 '20 at 11:09
Because if I try to do the map without converting to an array first it gives me this [ undefined, undefined, undefined, undefined, undefined, undefined ] – dethm0r Dec 26 '20 at 11:11
Not sure, if your data is like you've given in the question, it should have been fine? If it were an object, map would not run, so probably there's something else going on – Sudhanshu Kumar Dec 26 '20 at 11:14

Retrive certains keys from an Object

2 Answers2