How to concat string properties of an array in an array of arrays and create a new property in each array

Question

I have an array of arrays which looks like below:

UserList=[
[name:"user1", type:"admin", location:"NY", expired:"NO"],
[name:"user2", type:"poweruser", location:"CO", expired:"NO"],
[name:"user3", type:"admin", location:"SF", expired:"NO"],
]

I want to add the three properties name, type and location and create a new property in each individual array like the property "AllProps" in the below example:

Desired Output:

UserList=[
[name:"user1", type:"admin", location:"NY", expired:"NO",AllProps:"user1adminNY"],
[name:"user2", type:"poweruser", location:"CO", expired:"NO",AllProps:"user1poweruserCO"],
[name:"user3", type:"admin", location:"SF", expired:"NO", AllProps:"user1adminSF"],
]

Can I do this using Loadash? What is the best and fastest way to do this?

Zohaib Ijaz · Accepted Answer · 2018-04-25 15:28:35Z

2

You are using {} but it should be [] for array. Also you need to use : instead of = in objects

var userList= [
{name: "user1", type: "admin", location: "NY", expired: "NO"},
{name: "user2", type: "poweruser", location: "CO", expired: "NO"},
{name: "user3", type: "admin", location: "SF", expired: "NO"}
];

var output = userList.map(user => {
   user.AllProps = user.name + user.type + user.location;
   return user;
});

// Short hand
var output = userList.map(user => ({ ...user, AllProps: user.name + user.type + user.location}));

console.log('output:', output);

edited Apr 25, 2018 at 15:28

answered Apr 24, 2018 at 23:00

Zohaib Ijaz

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Comments

Matt · Accepted Answer · 2018-04-25 11:37:45Z

1

Based on your requirements and wanting to just modify your existing array without return a new one, simply iterate the array and add the key/value pair:

var UserList = [
	{name: "user1", type: "admin", location: "NY", expired: "NO"},
	{name: "user2", type: "poweruser", location: "CO", expired: "NO"},
	{name: "user3", type: "admin", location: "SF", expired: "NO"},
];

UserList.forEach(function(x){
	x["AllProps"] = x.name + x.type + x.location;
});	

console.log(UserList);

The upvoted answer will work fine, but there is no need to return anything.

answered Apr 25, 2018 at 11:37

Matt

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Comments

ernesthm · Accepted Answer · 2018-04-24 23:09:23Z

I think something like this is that you need:

_.forEach(UserList, function(u){
  var allPropValues = "";
  _.forOwn(u, function(value, key) {
     if(key !== 'expired') {
        allPropValues += value;
     }
  });  
  u.AllProps = allPropValues;
});

var UserList=[
{name:"user1", type:"admin", location:"NY", expired:"NO"},
{name:"user2", type:"poweruser", location:"CO", expired:"NO"},
{name:"user3", type:"admin", location:"SF", expired:"NO"},
];
console.log({before: UserList});

_.forEach(UserList, function(u){
  var allPropValues = "";
  _.forOwn(u, function(value, key) {
     if(key !== 'expired') {
        allPropValues += value;
     }
  });  
  u.AllProps = allPropValues;
});

console.log({after: UserList});

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.9/lodash.js"></script>

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