array.push（object）未在javascript循环的末尾推送

Question

var temparray1 = [[1,3,4],[5,6,7],[8,9,10]];
var final = [];
var obj = {};
for(var temp in temparray1){
    for(var test in temparray1[temp]){
        obj.b = temparray1[temp][0];
        obj.c = temparray1[temp][1];
        obj.d = temparray1[temp][2];
    }
    console.log(obj);
    final.push(obj);
}

current output

[{ b: 8, c: 9, d: 10 }
{ b: 8, c: 9, d: 10 }
{ b: 8, c: 9, d: 10 }]

expected Out put :

[{ b: 1, c: 3, d: 4 }
{ b: 5, c: 6, d: 7 }
{ b: 8, c: 9, d: 10 }]

i am running my javascript in node.js -v 8.1.x server

in the console at the end of the for loop it prints the required out put but not in the array push

Answer 1

Probably, you set obj outside the for loop, therefore the props are overwritten and you push the same object multiple times into the array. Simply move the obj declaration into the loop. And you probably just need the outer loop.

Btw much shorter:

let final = temparray1.map(
 ([b,c,d]) => ({b,c,d})
);

Answer 2

Here is what you wanted

var temparray1 = [[1,3,4],[5,6,7],[8,9,10]];
var final = [];
for(var temp in temparray1){
   var obj = {};
   obj['b'] = temparray1[temp][0];
   obj['c'] = temparray1[temp][1];
   obj['d'] = temparray1[temp][2];
   final.push(obj);
}
console.log(final);

Hope this helps!

Answer 3

 var temparray = [[1, 3, 4], [5, 6, 7], [8, 9, 10]]; const final = temparray.map(a => ({ b: a[0], c: a[1], d: a[2] })); console.log(final); 

Answer 4

You could use Array#map and return an object with the wanted properties.

 var array = [[1, 3, 4], [5, 6, 7], [8, 9, 10]], result = array.map(function (a) { return { b: a[0], c: a[1], d: a[2] }; }); console.log(result); 

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

With ES6, you could map the inner arrays as well with an array for the keys with Object.assign and spread syntax ... .

 var array = [[1, 3, 4], [5, 6, 7], [8, 9, 10]], keys = ['b', 'c', 'd'], result = array.map(a => Object.assign(...keys.map((k, i) => ({ [k]: a[i] })))); console.log(result); 

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