How to iterate over object values in an array?

Question

I have an object like this:

{
  username: {
    hobby: [
      {
        hobby1: "cricket",
        hobby2: "swim"
      },
      {
        hobby3: "dance",
        hobby4: "zumba"
      }
    ]
  }
}

I can easily do a forEach and do console.log(item) but what if I just want the values cricket,swim,dance,zumba alone (don’t need hobby1 through hobby4). Can someone show me how to extract the values alone?

The question is not clear. Where is `hobbies` in the object? — brk, Aug 30 '17 at 05:33

adeneo · Answer 1 · 2017-08-30T05:42:26.780

1

If you want an object with just the hobbies, you can reduce the array to return that

var obj = {
  username: {
    hobby: [{
        hobby1: "cricket",
        hobby2: "swim"
      },
      {
        hobby3: "dance",
        hobby4: "zumba"
      }
    ]
  }
}

var obj2 = obj.username.hobby.reduce((a, b) => {
  Object.entries(b).forEach(x => a[x[0]] = x[1]); return a;
}, {})

console.log(obj2);
console.log(Object.values(obj2)); // just the values

edited Aug 30 '17 at 05:42

answered Aug 30 '17 at 05:39

adeneo

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Syntax error. Can resolve it? – Ramesh Rajendran Aug 30 '17 at 05:40
@RameshRajendran - then get a proper browser – adeneo Aug 30 '17 at 05:40
IE 11 is not a proper browser? – Ramesh Rajendran Aug 30 '17 at 05:41
No, it's not, it doesn't support `Object.entries` or arrow functions – adeneo Aug 30 '17 at 05:41
Then how can we accept it is a good answer to OP, if the OP using this same browser? – Ramesh Rajendran Aug 30 '17 at 05:42
1

Are you saying I shouldn't use ES6 in my answers, because you're using an outdated browser ? – adeneo Aug 30 '17 at 05:43
@RameshRajendran This is ES6 syntax which has been the officially released standard for two years. You should know that this is ES6, you should know that your browser can’t keep up with the standard. – Sebastian Simon Aug 30 '17 at 05:44

score 1 · Answer 2 · answered Aug 30 '17 at 05:44

Try this, what i understand is that you just need "hobbies" as value not they indexes

var json= {
        username: {
           hobby: [{
               hobby1: "cricket",
               hobby2: "swim"
           },
           {
               hobby3: "dance",
               hobby4: "zumba"
           }]
         }
       }    ;

var hobbies=json.username.hobby;

var hobbies_arr=[];
var i=0;
for(var item in hobbies){
     item=hobbies[item];          
     for(var hobby in item){
         hobby=item[hobby];
         hobbies_arr[i]=hobby;
         i++;
     }
}

console.log(hobbies_arr);

Out put would be

Array [ "cricket", "swim", "dance", "zumba" ]

score 0 · Accepted Answer · answered Aug 30 '17 at 05:45

You can easily loop through the objects and arrays using a for within a for like this:

let obj = {
      username: {
          hobby: [
              {
                  hobby1: "cricket",
                  hobby2: "swim"
              },
              {
                  hobby3: "dance",
                  hobby4: "zumba"
              }
          ]
     }
}

for(let hobbies of obj.username.hobby) {
    for(let hobby in hobbies) {
          console.log(hobbies[hobby])
    }
}

score 0 · Answer 4 · answered Aug 30 '17 at 05:47

You can use array#reduce to accumulate all your hobbies in an array.

var obj = {username: {hobby: [{hobby1: "cricket",hobby2: "swim"},{hobby3: "dance",hobby4: "zumba"}]}};

var result = obj.username.hobby.reduce((res, obj) => res.concat(Object.values(obj)), []);

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

How to iterate over object values in an array?

4 Answers4