sort index javascript code example

Example 1: javascript sort array of objects

const books = [
  {id: 1, name: 'The Lord of the Rings'},
  {id: 2, name: 'A Tale of Two Cities'},
  {id: 3, name: 'Don Quixote'},
  {id: 4, name: 'The Hobbit'}
]

compareObjects(object1, object2, key) {
  const obj1 = object1[key].toUpperCase()
  const obj2 = object2[key].toUpperCase()

  if (obj1 < obj2) {
    return -1
  }
  if (obj1 > obj2) {
    return 1
  }
  return 0
}

books.sort((book1, book2) => {
  return compareObjects(book1, book2, 'name')
})

// Result:
// {id: 2, name: 'A Tale of Two Cities'}
// {id: 3, name: 'Don Quixote'}
// {id: 4, name: 'The Hobbit'}
// {id: 1, name: 'The Lord of the Rings'}

Example 2: js index sorted

var test = ['b', 'c', 'd', 'a'];
var len = test.length;
var indices = new Array(len);
for (var i = 0; i < len; ++i) indices[i] = i;
indices.sort(function (a, b) { return test[a] < test[b] ? -1 : test[a] > test[b] ? 1 : 0; });
console.log(indices);

Example 3: javascript sort

var numbers = [4, 2, 5, 1, 3];
numbers.sort(function(a, b) {
  return a - b;
});
console.log(numbers);

// [1, 2, 3, 4, 5]