let array = [0,1,2,3,4];
array.__proto__ = null;
array.pop();
console.log(array.pop());

What is the output above snippet in javacsirpt?

    A) 3.
    B) 4.
    C) Error.
    D) undefined.

The correct answer is:

C) Error.

Explanation:
- The code snippet attempts to set the `__proto__` property of the array to null, effectively removing the array's prototype linkage.
- After setting `array.__proto__ = null;`, the array loses its connection to the Array prototype methods.
- When `array.pop()` is called, it results in an error because the `pop()` method is not accessible due to the removal of the prototype linkage.
- Therefore, attempting to call `array.pop()` after removing the prototype linkage results in a runtime error.



2. var index = 0;
while(index < 5){
setTimeout(()=>{
    console.log(index);
},1);
index++;
}

What is the output above snippet?


    A) 0 0 0 0 0.
    B) 0 1 2 3 4.
    C) 4 4 4 4 4.
    D) 5 5 5 5 5.

The correct answer is:

D) 5 5 5 5 5.

Explanation:
- This code snippet creates a `setTimeout` function inside a while loop.
- The `setTimeout` function schedules the execution of the provided function (which logs the value of `index`) after a specified delay (1 millisecond in this case).
- However, the `setTimeout` function does not block the execution of the loop. So, by the time the callback function is executed, the value of `index` will have already reached 5.
- Therefore, when the callback function executes, it will log the current value of `index`, which is 5, for all iterations of the loop.
- As a result, the output will be `5 5 5 5 5`.






3.

function example(num){
{
 let value = num;
}
console.log(value);
var value = 30;
}
example(10);
What is the output above snippet?

    A) 10.
    B) Error, “value is not defined”
    C) undefined.
    D) 30.


The correct answer is:

B) Error, “value is not defined”

Explanation:
- The `value` variable is declared using `let` inside the `example` function, which means it has block scope and is only accessible within the block where it's declared.
- Therefore, when `console.log(value)` is called outside the block where `value` is declared, it will result in an error because `value` is not defined in that scope.
- Hence, the output will be an error stating "value is not defined."


4.
let x = 10;
function exampleG(){
console.log(x+x);
}


function example(){
var x = 20;
exampleG();
return function(){
    console.log(x+x);
}
}
example()();


What is the output above snippet?

A)   20 20.
B)  40 40.
C) 40 20.
D) 20 40.

The correct answer is:

C) 40 20.

Explanation:
- Inside the `example` function, a local variable `x` with a value of 20 is declared using `var`.
- When `exampleG()` is called from within `example`, it accesses the global variable `x`, which has a value of 10.
- So, `console.log(x+x)` inside `exampleG()` outputs `10 + 10 = 20`.
- Then, the returned function from `example()` is immediately invoked, and it logs the value of the local variable `x` (which is 20) twice, resulting in `20 + 20 = 40` for the second output.



5.

function getName() {
  if (true) {
    let name = 'Raghul';
    if (false) {
      let name = 'Gokul';
      if (true) {
        console.log(name);
      }
      name = undefined;
    }// false end bracket
    console.log(name);
    name = null;
  }// true end bracket
}

getName();

What will be logged to the console after executing the getName() function ?

    A) Raghul
    B) null
    C) undefined
    D) Gokul


The correct answer is:

```
A) Raghul
```

Explanation:
- Inside the `getName` function, the first `if` block is always true, so it executes.
- Within this block, a variable `name` is declared and assigned the value `'Raghul'`.
- Then, the second `if` block is false, so it does not execute.
- The `console.log(name)` statement within the first `if` block logs the value of the `name` variable, which is `'Raghul'`.
- After that, `name` is assigned `null` before the function returns. However, this assignment does not affect the logged value.



6.

**Question:**

Consider the following JavaScript code snippet:

```javascript
function addition(a) {
  return (b) => {
    return b + a;
  };
}

const a = addition(2);
const b = addition(3);
console.log(a(7));
console.log(b(9));
```

What will be the output of the above code snippet?

A) Throw an error
B) 7, 9
C) 8, 9
D) 9, 12

**Answer:**
D) 9, 12

This JavaScript code defines a function `addition` that takes a parameter `a` and returns a function that takes another parameter `b` and adds `a` to `b`.

- `const a = addition(2);` creates a closure where `a` is 2, so `a` becomes a function that adds 2 to its argument.
- `const b = addition(3);` creates another closure where `a` is 3, so `b` becomes a function that adds 3 to its argument.

When `a(7)` is called, it adds 2 to 7, resulting in 9.
When `b(9)` is called, it adds 3 to 9, resulting in 12.

So, the output will be:

D) 9, 12

7.
Calculate number of days between 2020/08/01 and 2020/01/01 in javascript?

// Define the two dates
const date1 = new Date('2020/08/01');
const date2 = new Date('2020/01/01');

// Calculate the difference in milliseconds
const differenceMs = date1 - date2;

// Convert milliseconds to days
const daysDifference = Math.floor(differenceMs / (1000 * 60 * 60 * 24));

console.log('Number of days between the two dates:', daysDifference);