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JavaScript: Sort an array of JavaScript objects

JavaScript Object: Exercise-10 with Solution

Write a JavaScript program to sort an array of JavaScript objects.

Sample Object:

var library = [ 
   {
       title:  'The Road Ahead',
       author: 'Bill Gates',
       libraryID: 1254
   },
   {
       title: 'Walter Isaacson',
       author: 'Steve Jobs',
       libraryID: 4264
   },
   {
       title: 'Mockingjay: The Final Book of The Hunger Games',
       author: 'Suzanne Collins',
       libraryID: 3245
   }];

Expected Output:

[[object Object] {
  author: "Walter Isaacson",
  libraryID: 4264,
  title: "Steve Jobs"
}, [object Object] {
  author: "Suzanne Collins",
  libraryID: 3245,
  title: "Mockingjay: The Final Book of The Hunger Games"
}, [object Object] {
  author: "The Road Ahead",
  libraryID: 1254,
  title: "Bill Gates"
}]

Sample Solution: -

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript program to sort an array of JS objects</title>
</head>
<body>

</body>
</html>

JavaScript Code:

var library = [ 
   {
       title: 'Bill Gates',
       author: 'The Road Ahead',
       libraryID: 1254
   },
   {
       title: 'Steve Jobs',
       author: 'Walter Isaacson',
       libraryID: 4264
   },
   {
       title: 'Mockingjay: The Final Book of The Hunger Games',
       author: 'Suzanne Collins',
       libraryID: 3245
   }];

var sort_by = function(field_name, reverse, initial){

   var key = initial ?
       function(x)
             {
               return initial(x[field_name]);
             } :
       function(x) 
             {
               return x[field_name];
             };

   reverse = !reverse ? 1 : -1;

   return function (x, y) {
       return x = key(x), y = key(y), reverse * ((x > y) - (y > x));
     } ;
};


var newobj = library.sort(sort_by('libraryID', true, parseInt));

console.log(newobj);

Sample Output:

[{"title":"Steve Jobs","author":"Walter Isaacson","libraryID":4264},{"title":"Mockingjay: The Final Book of The Hunger Games","author":"Suzanne Collins","libraryID":3245},{"title":"Bill Gates","author":"The Road Ahead","libraryID":1254}]

Flowchart:

Flowchart: JavaScript - Sort an array of JavaScript objects.

Live Demo:

See the Pen javascript-object-exercise-10 by w3resource (@w3resource) on CodePen.


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Previous: Write a JavaScript program to calculate the area and perimeter of a circle. Create two methods to calculate the area and perimeter. The radius of the circle will be supplied by the user.
Next: Write a JavaScript function to print all the methods in an JavaScript object.

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JavaScript: Tips of the Day

How to remove a specific item from an array?

Find the index of the array element you want to remove using indexOf, and then remove that index with splice.

The splice() method changes the contents of an array by removing existing elements and/or adding new elements.

const array = [2, 5, 9];

console.log(array);

const index = array.indexOf(5);
if (index > -1) {
  array.splice(index, 1);
}

// array = [2, 9]
console.log(array);

The second parameter of splice is the number of elements to remove. Note that splice modifies the array in place and returns a new array containing the elements that have been removed.

For the reason of completeness, here are functions. The first function removes only a single occurrence (i.e. removing the first match of 5 from [2,5,9,1,5,8,5]), while the second function removes all occurrences:

function removeItemOnce(arr, value) {
  var index = arr.indexOf(value);
  if (index > -1) {
    arr.splice(index, 1);
  }
  return arr;
}

function removeItemAll(arr, value) {
  var i = 0;
  while (i < arr.length) {
    if (arr[i] === value) {
      arr.splice(i, 1);
    } else {
      ++i;
    }
  }
  return arr;
}
//Usage
console.log(removeItemOnce([2,5,9,1,5,8,5], 5))
console.log(removeItemAll([2,5,9,1,5,8,5], 5))

Ref: https://bit.ly/2N9nKRp