JavaScript: Get the last element of an array

JavaScript Array: Exercise-4 with Solution

Last Elements of Array

Write a JavaScript function to get the last element of an array. Passing the parameter 'n' will return the last 'n' elements of the array.

Test Data :
console.log(last([7, 9, 0, -2]));
console.log(last([7, 9, 0, -2],3));
console.log(last([7, 9, 0, -2],6));

Visual Presentation:

Sample Solution:

JavaScript Code:

// Function to get the last n elements of an array
var last = function(array, n) {
  // Check if the input array is null, return undefined if true
  if (array == null) 
    return void 0;

  // Check if the value of n is null, return the last element of the array if true
  if (n == null) 
    return array[array.length - 1];

  // Use the slice method to get the last n elements of the array
  // Math.max is used to ensure the starting index is not negative
  return array.slice(Math.max(array.length - n, 0));
};

// Testing the function with various cases
console.log(last([7, 9, 0, -2]));
console.log(last([7, 9, 0, -2], 3));
console.log(last([7, 9, 0, -2], 6));

Output:

-2
[9,0,-2]
[7,9,0,-2]

Flowchart:

ES6 Version:

// Function to get the last n elements of an array
const last = (array, n) => {
  // Check if the input array is null, return undefined if true
  if (array == null)
    return undefined;

  // Check if the value of n is null, return the last element of the array if true
  if (n == null)
    return array[array.length - 1];

  // Use the slice method to get the last n elements of the array
  // Math.max is used to ensure the starting index is not negative
  return array.slice(Math.max(array.length - n, 0));
};

// Testing the function with various cases
console.log(last([7, 9, 0, -2]));
console.log(last([7, 9, 0, -2], 3));
console.log(last([7, 9, 0, -2], 6));

Live Demo:

See the Pen JavaScript - Get the last element of an array- array-ex-4 by w3resource (@w3resource) on CodePen.

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