Get array from the object in ES5 equivalent

Question

coursesCompleted [
  {
    "coursename": "ITSM",
    "relatedTests": [
      {
        "testid": "8a754f2cdbf85700bde15901cf9619dc",
        "testname": "Project plan Fundamentals"
      },
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "7ce4fa53dbe0d300bde15901cf96192f"
  },
  {
    "coursename": "CSA",
    "relatedTests": [
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "fea27b96db285300bde15901cf96194b"
  }]

Form this object I want to get relatedTests array which has "courseid": "7ce4fa53dbe0d300bde15901cf96192f"

how can i do this.?

Possible duplicate of [Get JavaScript object from array of objects by value or property](https://stackoverflow.com/questions/13964155/get-javascript-object-from-array-of-objects-by-value-or-property) — messerbill, Mar 13 '18 at 12:24

score 1 · Answer 1 · answered Mar 13 '18 at 12:25

You have to use array.filter.

See online documentation: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter

const coursesCompleted = [
  {
    "coursename": "ITSM",
    "relatedTests": [
      {
        "testid": "8a754f2cdbf85700bde15901cf9619dc",
        "testname": "Project plan Fundamentals"
      },
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "7ce4fa53dbe0d300bde15901cf96192f"
  },
  {
    "coursename": "CSA",
    "relatedTests": [
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "fea27b96db285300bde15901cf96194b"
  }]
  
  console.log(


  coursesCompleted.filter((item) => {
    return item.courseid === '7ce4fa53dbe0d300bde15901cf96192f'
  })[0].relatedTests


  );

score 1 · Answer 2 · answered Mar 13 '18 at 12:25

Use find() on the array coursesCompleted to find out the item for requested courseId.

And then get the relatedTests from the returned object;

let coursesCompleted =  [
  {
    "coursename": "ITSM",
    "relatedTests": [
      {
        "testid": "8a754f2cdbf85700bde15901cf9619dc",
        "testname": "Project plan Fundamentals"
      },
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "7ce4fa53dbe0d300bde15901cf96192f"
  },
  {
    "coursename": "CSA",
    "relatedTests": [
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "fea27b96db285300bde15901cf96194b"
  }]
  
let output = coursesCompleted.find(a => a.courseid == "7ce4fa53dbe0d300bde15901cf96192f").relatedTests

console.log(output)

gurvinder372 · Accepted Answer · 2018-03-13T14:35:04.833

I want to get relatedTests array which has "courseid": "7ce4fa53dbe0d300bde15901cf96192f"

Use reduce

var courseId = "7ce4fa53dbe0d300bde15901cf96192f";
var output = coursesCompleted.reduce( ( acc, c ) => 
    acc.concat( c.courseid == courseId ? c.relatedTests : [] ) ,[]) ;

Demo

var coursesCompleted = [{
    "coursename": "ITSM",
    "relatedTests": [{
        "testid": "8a754f2cdbf85700bde15901cf9619dc",
        "testname": "Project plan Fundamentals"
      },
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "7ce4fa53dbe0d300bde15901cf96192f"
  },
  {
    "coursename": "CSA",
    "relatedTests": [{
      "testid": "aaf18ceedb285300bde15901cf961934",
      "testname": "Admin"
    }],
    "courseid": "fea27b96db285300bde15901cf96194b"
  }
];

var courseId = "7ce4fa53dbe0d300bde15901cf96192f";
var output = coursesCompleted.reduce((acc, c) =>
  acc.concat(c.courseid == courseId ? c.relatedTests : []), []);
console.log( output );

Note

This answer assumes that there could be multiple rows with same courseId

ES5 equivalent

var output = coursesCompleted.reduce( function( acc, c ) { 
    return acc.concat( c.courseid == courseId ? c.relatedTests : [] ) 
},[]) ;

is there any other method.? when I use this `filter` or `find ` this is the error I am getting `Error: expected identifier instead of saw near '>'` it's not pure jquery. `serview now client script`some basic jquery stuff will work. — Mr world wide, Mar 13 '18 at 14:33
@Mrworldwide From the error it appears that your browser doesn't support arrow functions yet, hence shared an ES5 equivalent function. — gurvinder372, Mar 13 '18 at 14:39
Thank you so much for helping it worked. I learn something new today because of you. — Mr world wide, Mar 13 '18 at 14:44

Prashanth KR · Answer 4 · 2018-03-13T12:28:55.553

1

var coursesCompleted =

[
  {
    "coursename": "ITSM",
    "relatedTests": [
      {
        "testid": "8a754f2cdbf85700bde15901cf9619dc",
        "testname": "Project plan Fundamentals"
      },
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "7ce4fa53dbe0d300bde15901cf96192f"
  },
  {
    "coursename": "CSA",
    "relatedTests": [
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "fea27b96db285300bde15901cf96194b"
  }];
  
var course=  coursesCompleted.filter((course)=> course.courseid=="7ce4fa53dbe0d300bde15901cf96192f");
console.log(course[0].relatedTests)

edited Mar 13 '18 at 12:28

answered Mar 13 '18 at 12:26

Prashanth KR

294
2
8

the request is to have `relatedTests` – ben Mar 13 '18 at 12:27
got it and edited the post according to the request. Thanks for notifying. – Prashanth KR Mar 13 '18 at 12:29

score 1 · Answer 5 · answered Mar 13 '18 at 12:29

let coursesCompleted = [{
    "coursename": "ITSM",
    "relatedTests": [{
        "testid": "8a754f2cdbf85700bde15901cf9619dc",
        "testname": "Project plan Fundamentals"
      },
      {
        "testid": "aaf18ceedb285300bde15901cf961934",
        "testname": "Admin"
      }
    ],
    "courseid": "7ce4fa53dbe0d300bde15901cf96192f"
  }, {
    "coursename": "CSA",
    "relatedTests": [{
      "testid": "aaf18ceedb285300bde15901cf961934",
      "testname": "Admin"
    }],
    "courseid": "fea27b96db285300bde15901cf96194b"
  }
]

let result = coursesCompleted.filter(x => x.courseid==='7ce4fa53dbe0d300bde15901cf96192f')[0].relatedTests

console.log(result)

Get array from the object in ES5 equivalent

5 Answers5