For example I have this arrays:

a = [1, 2, 3];
b = ["a", "b", "c"];

I want to make one object from these arrays that would look like this:

c = [{
  a: 1,
  b: "a"
},
{
  a: 2,
  b: "b"
},
{
  a: 3,
  b: "c"
}];

For example I have this arrays:

a = [1, 2, 3];
b = ["a", "b", "c"];

I want to make one object from these arrays that would look like this:

c = [{
  a: 1,
  b: "a"
},
{
  a: 2,
  b: "b"
},
{
  a: 3,
  b: "c"
}];

• javascript
• arrays
• node.js
• object

• 4 what did you try? – Giannis Mp Commented Jul 13, 2018 at 11:18
• I made one empty array containing certain number of objects like this c = [{ a: 0, b: 0 },{ a: 0, b: 0 },{ a: 0, b: 0 }] and then with for loop i filed in data but this is really bad if I had 100+ arrays – mesopotamija9 Commented Jul 13, 2018 at 11:21
• 1 Check Nikhil's answer – Giannis Mp Commented Jul 13, 2018 at 11:22

6 Answers 6

You can use Array.map

let a = [1, 2, 3];
let b = ["a", "b", "c"];
let c = a.map((v,i) => ({a:v, b: b[i]}));
console.log(c);

You can use Array#reduce to do something like this perhaps:

var a = [1, 2, 3];
var b = ["a", "b", "c"];

var c = a.reduce((accumulator, e, index) => {
  return accumulator.concat({a: e, b: b[index]});
}, [])

console.log(c);

You can use a for-loop like this:

    var a = [1, 2, 3];
    var b = ["a", "b", "c"];

    var c = [];

    for (var i = 0; i < a.length; i ++) {
        c[i] = {'a': a[i], 'b': b[i]};
    }
    console.log(c);

You can use Array.forEach() loop for that:

var a = [1, 2, 3];
var b = ["a", "b", "c"];
var c = [];
a.forEach((item, index)=>{
  c.push({a: item, b: b[index]});
});
console.log(c);

You could take an object with an arbitrary count of properties and generate an array of objects.

var a = [1, 2, 3],
    b = ["a", "b", "c"],
    result = Object
        .entries({ a, b })
        .reduce((r, [k, a]) => {
            a.forEach((v, i) => Object.assign(r[i] = r[i] || {}, { [k]: v }));
            return r;
        }, []);
    
console.log(result);

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Traditional but patible way

Note: Most solutions in this page don't check if variables a and b have the same length

var a = [1, 2, 3];
var b = ["a", "b", "c"];

function bine(a,b){
        
    if (a.length === b.length){ // Check if both arrays have same length  
      var arr = []; // Make an empty array
      for(var i=0; i<a.length; i++){ // iterate every element of the array
          var obj = {} // Make an empty object
          obj["a"] = a[i];
          obj["b"] = b[i];
          arr.push(obj);
      }
    }else{        
        throw "Arrays don't have the same length";
    }
    
    return arr;
}

bine(a, b); // Use it like a function