JavaScript

1.Write a JavaScript code to add an element to the end of an array using the 
push method.
Example: [1, 2, 3] → [1, 2, 3, 4]
var arr = [1, 2, 3];
arr.push(4);
console.log(arr);
// Output: [1, 2, 3, 4]


2.Write a JavaScript code to remove the last element from an array using the pop 
method.
Example: [1, 2, 3, 4] → [1, 2, 3]
var arr = [1, 2, 3, 4];
arr.pop();
console.log(arr);
// Output: [1, 2, 3]


3.Write a JavaScript code to add an element to the beginning of an array using
 the unshift method.
Example: [2, 3, 4] → [1, 2, 3, 4]
var arr = [2, 3, 4];
arr.unshift(1);
console.log(arr);
// Output: [1, 2, 3, 4]


4.Write a JavaScript code to remove the first element from an array using the
 shift method.
Example: [1, 2, 3, 4] → [2, 3, 4]
var arr = [1, 2, 3, 4];
arr.shift();
console.log(arr);
// Output: [2, 3, 4]


5.Write a JavaScript code to convert an array into a string using the join 
method.
Example: [1, 2, 3] → "123"
var arr = [1, 2, 3];
var x = arr.join("");
console.log(x);
// Output: "123"


Choose the Correct Answer:

1. What will be the output of [1, 2, 3, 4].pop()?
A) [1, 2, 3, 4]
B) [1, 2, 3]    ✓
C) [2, 3, 4]
D) Error
// Correct Answer: B) [1, 2, 3]
// pop() removes the last element from the array

2. What will be the output of [1, 2, 3].push(4)?
A) [1, 2, 3]
B) [1, 2, 3, 4]    ✓
C) [4, 1, 2, 3]
D) Error
// Correct Answer: B) [1, 2, 3, 4]
// push(4) adds 4 to the end of the array

3. What will be the output of [1, 2, 3, 4].shift()?
A) [1, 2, 3, 4]
B) [2, 3, 4]    ✓
C) [1, 2, 3]
D) Error
// Correct Answer: B) [2, 3, 4]
// shift() removes the first element from the array

4. What will be the output of [2, 3, 4].unshift(1)?
A) [2, 3, 4]
B) [1, 2, 3, 4]    ✓
C) [1, 3, 4]
D) Error
// Correct Answer: B) [1, 2, 3, 4]
// unshift(1) adds 1 to the beginning of the array

5. What will be the output of [1, 2, 3].join("")?
A) 123    ✓
B) [1, 2, 3]
C) 1 2 3
D) Error
// Correct Answer: A) 123
// join("") combines all elements into a string with no separator