How to get single array from multiple array in javascript

Question

I have array like this

   var arr = [
                [ {"c": 1},{"d": 2} ],
                [ {"c": 2},{"d": 3} ]
             ]

I want to change into (by javascript only)

var newArr  = [{"c": 1},{"d": 2},{"c": 2},{"d": 3}]

I have tried this by map but not getting expected output .

http://stackoverflow.com/questions/10865025/merge-flatten-an-array-of-arrays-in-javascript [duplicate] — Denis Tsoi, Feb 16 '17 at 08:47
with a recursive function, testing if isArray the element of a array — Álvaro Touzón, Feb 16 '17 at 08:47

score 10 · Answer 1 · answered Feb 16 '17 at 08:47

10

You can use reduce() and spread syntax.

 var arr = [
  [ {"c": 1},{"d": 2} ],
  [ {"c": 2},{"d": 3} ]
]

var result = arr.reduce((r, e) => (r.push(...e), r), [])
console.log(result)

answered Feb 16 '17 at 08:47

Nenad Vracar

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I wish I could upvote this more than once, beautiful answer! – Jackthomson Feb 16 '17 at 08:50

score 2 · Answer 2 · answered Feb 16 '17 at 08:56

You could use Array#reduce with Array#concat.

var arr = [[{ c: 1 }, { d: 2 }], [{ c: 2 }, { d: 3 }]],
    result = arr.reduce((r, a) => r.concat(a), []);

console.log(result)

ES5

var arr = [[{ c: 1 }, { d: 2 }], [{ c: 2 }, { d: 3 }]],
    result = arr.reduce(function (r, a) { return r.concat(a); }, []);

console.log(result)

score 1 · Answer 3 · answered Feb 16 '17 at 08:50

In plain JavaScript you can do this using Array.portotype.forEach.

var arr = [
                [ {"c": 1},{"d": 2} ],
                [ {"c": 2},{"d": 3} ]
             ];
             
var newArray = [];

arr.forEach(function(e){
 e.forEach(function(e1){
  newArray.push(e1);
 });
})

console.log(newArray);

Use this..

How to get single array from multiple array in javascript

3 Answers3