JavaScript: Get the difference between two given arrays

JavaScript fundamental (ES6 Syntax): Exercise-244 with Solution

Difference Between Arrays

Write a JavaScript program to get the difference between two given arrays.

• Create a Set from b to get the unique values in b.
• Use Array.prototype.filter() on a to only keep values not contained in b, using Set.prototype.has().

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
// Define a function 'difference' to find the difference between two arrays
const difference = (a, b) => {
  // Create a set 's' from array 'b'
  const s = new Set(b);
  // Return elements from array 'a' that are not present in set 's'
  return a.filter(x => !s.has(x));
};

// Test the 'difference' function with different arrays
console.log(difference([1, 2, 3], [1, 2, 4])); // Output: [3]
console.log(difference([1, 2, 4], [1, 2, 3])); // Output: [4]

Output:

[3]
[4]

Visual Presentation:

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-244-1 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript program that returns an array of elements present in the first array but not in the second.
• Write a JavaScript function that computes the difference between two arrays using filtering and indexOf.
• Write a JavaScript program that compares two arrays and returns a new array containing their asymmetric difference.
• Write a JavaScript function that uses Set operations to determine the elements unique to each array.

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