Day 4: Count Objects

Objective

In this challenge, we learn about iterating over objects. Check the attached tutorial for more details.

Task

Complete the function in the editor. It has one parameter: an array, a, of objects. Each object in the array has two integer properties denoted by x and y. The function must return a count of all such objects o in array a that satisfy o.x = o.y.

Constraints

• 5 <= n <= 10
• 1 <= x,y <= 100

Output Format

Return a count of the total number of objects o such that o.x = o.y. Locked stub code in the editor prints the returned value to STDOUT.

Sample Input 0

1
2
3
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5
6

5
1 1
2 3
3 3
3 4
4 5

Sample Output 0

1

2

Explanation 0

There are n = 5 objects in the objects array:

• Objects[0] = {x: 1, y: 1}
• Objects[1] = {x: 2, y: 3}
• Objects[2] = {x: 3, y: 3}
• Objects[3] = {x: 4, y: 4}
• Objects[4] = {x: 5, y: 5}

Because we have two objects o that satisfy o.x = o.y (i.e., Objects[0] and Objects[2]), we return 2 as our answer.

Solution

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/*
 * Return a count of the total number of objects 'o' satisfying o.x == o.y.
 *
 * Parameter(s):
 * objects: an array of objects with integer properties 'x' and 'y'
 */
function getCount(objects) {
  return objects.reduce((target, item) => {
    item.x === item.y && (target += 1);

    return target;
  }, 0);
}