CODEWITHSUNDEEP
javascriptlodash
sithumc
sithumc

Reputation: 3404

How to set specific property value of all objects in a javascript object array (lodash)

I have following object array: 

var arr = [
  {
    id    : "a1",
    guid  : "sdfsfd",
    ...
    value : "abc",
    status: "active"
  },
  {
    id    : "a2",
    guid  : "sdfsfd",
    ...
    value : "def",
    status: "inactive"
  },
  {
    id    : "a2",
    guid  : "sdfsfd",
    ...
    value : "def"
  },
  ...
]

How to set "status" property of each object to "active". So the resulting array will be: 

var arr = [
  {
    id    : "a1",
    guid  : "sdfsfd",
    ...
    value : "abc",
    status: "active"
  },
  {
    id    : "a2",
    guid  : "sdfsfd",
    ...
    value : "def",
    status: "active"
  },
  {
    id    : "a2",
    guid  : "sdfsfd",
    ...
    value : "def",
    status: "active"
  },
  ...
]

Additionally this should create the property "active" if doesn't exists.

I can do this using for loops. But I'm pretty much sure lodash can do this in one line like: 

arr = _.set_property(arr, "status", "active");

Upvotes: 25

Views: 44654

Answers (3)

Legends
Legends

Reputation: 22672

You don't need lodash for this.

The first object is missing your status property and it will be added.


Showing two ways:


IMMUTABLE VERSION (We create a new array using map)

const arrImmutableVersion = arr.map(e => ({...e, status: "active"}));

MUTABLE VERSIONS (We change the original array)

arr.forEach((el)=>{el.status = "active";})

or

arr.forEach(function(el){el.status = "active";}) 


var arr = [
  {
    id    : "a1",
    guid  : "sdfsfd",   
    value : "abc"
  },
  {
    id    : "a2",
    guid  : "sdfsfd",   
    value : "def",
    status: "inactive"
  },
  {
    id    : "a2",
    guid  : "sdfsfd",   
    value : "def",
    status: "active"
  } 
];

// SHOWING THREE WAYS HOW YOU CAN DO IT

// MUTABLE VERSIONS - We change the original array
arr.forEach((el)=>{el.status = "active";}) // ES6
// or
arr.forEach(function(el){el.status = "active";}) 
//or
// IMMUTABLE VERSION - We create a new array using `map`
const arrImmutableVersion = arr.map(e => ({...e, status: "active"})); // ES6
//--------------------------------------------------------------


// RESULTS:
console.log("logging results of object 'arr'");
console.log(arr);
console.log("---------------------------------------------------------");
console.log("logging results of object 'arrImmutableVersion'");
console.log(arrImmutableVersion);

Upvotes: 29

Shady Smaoui
Shady Smaoui

Reputation: 1285

A way simpler and and cleaner way !

If you want to use func programming in a proper manner

  myArray = myArray.map(arrayElem => {
    arrayElem.property = newValue
    return arrayElem
  })

Upvotes: 3

random_user_name
random_user_name

Reputation: 26160

Indeed, you don't need Lodash, but the question is tagged Lodash, and using Lodash offers some useful defenses that reduces the risk of errors. This solution utilizes _.forEach and _.set

 // _.forEach won't throw errors if arr is not an array...
 _.forEach(arr, function (obj) {
    // _.set won't throw errors if obj is not an object. With more complex objects, if a portion of the path doesn't exist, _.set creates it
     _.set(obj, 'status', 'active');
 });

If you wanted to make it abstract, you could build a Lodash mixin:

_.mixin({
    setProperty: function(arr, key, val) {
        _.forEach(arr, function (obj) {
            _.set(obj, path, val);
        });
    }
});

Then, you could use it exactly as you described:

_.setProperty( arr, 'status', 'active' );

Upvotes: 13

Related Questions