how to return a specific key from an array

Question

please can anyone help me with some code to get specific data from an array here's is my array

var array = [
  {
    "name": "Joe",
    "age": 17
  },
  {
    "name": "Bob",
    "age": 17
  },
  {
    "name": "Carl",
    "age": 35
  }
]

just want to return name and its values without returning age

thanks in advance.

https://stackoverflow.com/questions/11922383/access-process-nested-objects-arrays-or-json — Teemu, Jul 24 '18 at 10:17
Please add an example of what you’d like to get as a result. Do you want an array of numbers or an array of objects with only that one element or only one specific number or... — JJJ, Jul 24 '18 at 10:22

score 5 · Answer 1 · answered Jul 24 '18 at 10:22

5

Use Array.map() with array destructuring method so that you get only the name key-value. Array.map() will have only one parameter so you do not need to mention return there:

var array = [ {"name":"Joe", "age":17},{"name":"Bob", "age":17},{"name":"Carl", "age": 35}];
var res = array.map(({name}) => ({name}));
console.log(res);

answered Jul 24 '18 at 10:22

Ankit Agarwal

30,378
5
37
62

Why create a new Array, from an Array? – Anuga Jul 24 '18 at 10:28
@Anuga -- You cannot keep downvoting other's answers just because you think that the result should not be this. Let OP comment what he expects, and then he will accept the answer which meets his requirements. – 31piy Jul 24 '18 at 10:38
I am not. Sorry. – Anuga Jul 24 '18 at 10:38

score 3 · Answer 2 · answered Jul 24 '18 at 11:30

Try using the jQuery.inArray() function. I hope it will help you.

   
    
    function functionname(){
     var names = [ {"name":"Joe", "age":17},{"name":"Bob", "age":17},{"name":"Carl", "age": 35}];
            var name = $('#name').val(); 
            if(jQuery.inArray(name, names)) {  
                alert(name +" Is In Array");  
            } else {  
                alert(name + ' Is NOT In Array...');  
            }  
    }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" name="name" id="name"/>
    <button onclick="functionname()" >Submit</button>

score 3 · Answer 3 · answered May 05 '21 at 22:21

In case if you want the value only, The following example will give you only names in a 1d array

var array = [ {"name":"Joe", "age":17},{"name":"Bob", "age":17},{"name":"Carl", "age": 35}];
var res = array.map(({name}) => (name));
console.log(res);

score 2 · Answer 4 · answered Jul 24 '18 at 10:19

2

You can use Array#map to do that. Destructure the name from the object and return a new object with only the name.

See the working demo below:

var array = [{
  "name": "Joe",
  "age": 17
}, {
  "name": "Bob",
  "age": 17
}, {
  "name": "Carl",
  "age": 35
}];

var result = array.map(({name, ...rest}) => ({name}));
console.log(result);

answered Jul 24 '18 at 10:19

31piy

23,323
6
47
67

Why create a new Array, from an Array? – Anuga Jul 24 '18 at 10:28
1

@Anuga -- Are you sure that OP doesn't want this? The statement _just want to return name and its values without returning age_ is confusing. That's why, the answers to return just the values are still there. – 31piy Jul 24 '18 at 10:29
Let's see Quote: ***Just want to return name*** – Anuga Jul 24 '18 at 10:31
1

@Anuga -- But why? The quote follows by _and its values_. – 31piy Jul 24 '18 at 10:33
Thanks Guys for you quick response, it's now working. Much appreciated – Jayvk1 Jul 24 '18 at 10:48
@Jayvk1 -- could you accept the answer which suits your needs? – 31piy Jul 24 '18 at 10:48

score 1 · Answer 5 · answered Jul 24 '18 at 10:16

1

Simple enough to access the name attribute of the object you simply need to reference the item in the array and select the name like so:

array[i].name;

answered Jul 24 '18 at 10:16

Sir Catzilla

321
3
18

score 1 · Answer 6 · answered Jul 24 '18 at 10:31

You could create a helper function to get a by property object off that array :

var persons = [
  {
    "name": "Joe",
    "age": 17
  },
  {
    "name": "Bob",
    "age": 17
  },
  {
    "name": "Carl",
    "age": 35
  }
];

function getElement(personList, property, comparable) {
  var arraySize = personList.length;
  for(var i = 0; i < arraySize; i++) {
     if (personList[i][property] == comparable) {
         return personList[i]
     }
  }
  return {"name":null, "age":null};
}

console.log(getElement(persons, "name", "Joe")); // outputs { "name": "John", "age" : 17}
console.log(getElement(persons, "name", "Fake John")); // outputs { "name": null, "age" :null}

This way you can retrieve your person object by any property he has.

Map uses less code, usually if you want simplicity you go with functional programming, in terms of efficiency, this way is better ;) — César Ferreira, Jul 24 '18 at 10:35
Why would you not just use the `Array.prototype.find` method for this? `persons.find((person) => person.name === 'Joe')` — fubar, Jul 25 '18 at 23:15

score -1 · Answer 7 · answered Jul 24 '18 at 10:26

All these Array.Map functions facepalm

var array = [
  {
    "name": "Joe",
    "age": 17
  },
  {
    "name": "Bob",
    "age": 17
  },
  {
    "name": "Carl",
    "age": 35
  }
]

array.forEach((entry) => {
  console.log(entry.name) /* Do whatever you want with `entry.name` */
})

how to return a specific key from an array

7 Answers7