Given the code let num = 10; const increaseNumber = () => num++; const num1 = increaseNumber(); console.log(num1); What will be the output of num1?

Given the code let num = 10; const increaseNumber = () => num++; const num1 = increaseNumber(); console.log(num1); What will be the output of num1?

• A. 10
• B. 11
• C. 12
• D. Undefined

Answer: (A)

In this code, the initial value of the variable `num` is set to 10. The function `increaseNumber` is defined as an arrow function that increments the value of `num` by 1 each time it is called, effectively returning the old value before incrementing. When `const num1 = increaseNumber();` is executed, the function `increaseNumber` is called. At this moment, it does the following: 1. It evaluates the current value of `num`, which is 10. 2. It then proceeds to execute the increment operation (`num++`), which first returns the current value of `num` (10) and then increments `num` to 11. The value returned by the function, which is now assigned to `num1`, is the original value of `num` before the increment occurred. Therefore, when the value of `num1` is logged in the console, it displays 10. This behavior of the post-increment operator (`num++`) is crucial in understanding why the output is 10. The increment happens after the original value is returned, leading to this particular output. Thus, the output of `num1` is 10.

In this code, the initial value of the variable num is set to 10. The function increaseNumber is defined as an arrow function that increments the value of num by 1 each time it is called, effectively returning the old value before incrementing.

When const num1 = increaseNumber(); is executed, the function increaseNumber is called. At this moment, it does the following:

1. It evaluates the current value of num, which is 10.

2. It then proceeds to execute the increment operation (num++), which first returns the current value of num (10) and then increments num to 11.

The value returned by the function, which is now assigned to num1, is the original value of num before the increment occurred. Therefore, when the value of num1 is logged in the console, it displays 10.

This behavior of the post-increment operator (num++) is crucial in understanding why the output is 10. The increment happens after the original value is returned, leading to this particular output. Thus, the output of num1 is 10.