JAVASCRIPT

merge 2 array of object by key

let arr1 = [
    { id: "abdc4051", date: "2017-01-24" },
    { id: "abdc4052", date: "2017-01-22" }
];

let arr2 = [
    { id: "abdc4051", name: "ab" },
    { id: "abdc4052", name: "abc" }
];

let arr3 = arr1.map((item, i) => Object.assign({}, item, arr2[i]));

console.log(arr3);
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js combine 2 array to object key value

var columns = ["Date", "Number", "Size", "Location", "Age"];
var rows = ["2001", "5", "Big", "Sydney", "25"];
var result =  rows.reduce(function(result, field, index) {
  result[columns[index]] = field;
  return result;
}, {})

console.log(result);

Merge array of objects into one object

const arrObj = [{a: 1, b: 2}, {c: 3, d: 4}, {e: 5, f: 6}];

console.log(arrObj.reduce(function(result, current) {
  return Object.assign(result, current);
}, {}));

// If you prefer arrow functions, you can make it a one-liner ;-)
console.log(arrObj.reduce(((r, c) => Object.assign(r, c)), {}));

// Thanks Spen from the comments. You can use the spread operator with assign
console.log(Object.assign({}, ...arrObj));
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