1. How is var a = 9? in this Javascript Challenge.I thought the increement is to happen after the substraction.

Question

Fill in the blank to output 3.

var a = ;
var b = 5;
b++;
alert(a - b)

2. What number will output 3, if b++ is substituted with ++b.

Answer 1

The 3rd statement, b++, is a standalone statement which increase b by 1.
Even if it is written in ++b, it does the same thing because it is a complete statement.

Therefore, before alert b is equal to 6, and 9 minus 6 equals to 3.

I put them into this code so you can see the action.
https://sololearn.com/compiler-playground/WFMJicdwt5H7/?ref=app

Answer 2

Dr Melchisedec Bankole ,

For the increment to happen after the subtraction, you'd have to write it like this.

alert(a - b++)

Answer 3

Code executes step by step so not possible of increment after substraction.