reorder object array 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: javascript sort array of object by property

function sortByDate( a, b ) {
  if ( a.created_at < b.created_at ){
    return -1;
  }
  if ( a.created_at > b.created_at ){
    return 1;
  }
  return 0;
}

myDates.sort(sortByDate);//myDates is not sorted.

Example 3: javascript sort array of objects by key value ascending and descending order

function compareValues(key, order = 'asc') {
  return function innerSort(a, b) {
    if (!a.hasOwnProperty(key) || !b.hasOwnProperty(key)) {
      // property doesn't exist on either object
      return 0;
    }

    const varA = (typeof a[key] === 'string')
      ? a[key].toUpperCase() : a[key];
    const varB = (typeof b[key] === 'string')
      ? b[key].toUpperCase() : b[key];

    let comparison = 0;
    if (varA > varB) {
      comparison = 1;
    } else if (varA < varB) {
      comparison = -1;
    }
    return (
      (order === 'desc') ? (comparison * -1) : comparison
    );
  };
}