JavaScript: Retrieve the value of a specified property from all elements in an array

Last update on May 30 2022 10:07:15 (UTC/GMT +8 hours)

JavaScript Array: Exercise-27 with Solution

Write a JavaScript function to retrieve the value of a given property from all elements in an array.

Sample array: [NaN, 0, 15, false, -22, '',undefined, 47, null]
Expected result: [15, -22, 47]

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Write a JavaScript function to retrieve the value of a given property from all elements in an array.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

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

function property_value(array, property_key) {
	var arr = [],
		index = -1,
		arrlen = array.length,array_items;

	while (++index < arrlen) {
		array_items = array[index];

  if (array_items.hasOwnProperty(property_key)) 
      {
	 arr[arr.length] = array_items[property_key];
      }
	}

	return arr;
}

console.log(property_value(library, 'title'));

console.log(property_value(library, 'author'));

Sample Output:

["The Road Ahead","Walter Isaacson","Mockingjay: The Final Book of The Hunger Games"]
["Bill Gates","Steve Jobs","Suzanne Collins"]

Flowchart:

ES6 Version:

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

function property_value(array, property_key) {
    const arr = [];
    let index = -1;
    const arrlen = array.length;
    let array_items;

    while (++index < arrlen) {
		array_items = array[index];

  if (array_items.hasOwnProperty(property_key)) 
      {
	 arr[arr.length] = array_items[property_key];
      }
	}

    return arr;
}

console.log(property_value(library, 'title'));

console.log(property_value(library, 'author'));

Live Demo:

See the Pen JavaScript - Retrieve the value of a specified property from all elements in an array - array-ex- 27 by w3resource (@w3resource) on CodePen.

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Previous: Write a JavaScript program to find a pair of elements (indices of the two numbers) from an given array whose sum equals a specific target number.
Next: Write a JavaScript function to find the longest common starting substring in a set of strings.

JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = []; arr[0] = "Jani"; arr[1] = "Hege"; arr[2] = "Stale"; arr[3] = "Kai Jim"; arr[4] = "Borge"; console.log(arr.join()); arr.splice(2, 0, "Lene"); console.log(arr.join());

Ref: https://bit.ly/2BXbp04