Can you explain these codes plz anf what is differnet between them??

Question

var a = 3
function b(){
a++
alert(a)
}
b()

&

var a = 3
alert(a++)

in the first shows 4

and in the second one shows 3

Answer 1

Post increment firstly do operation and secondly increment variable.

Then alert(a++) is the same as alert(a) a++.

Answer 2

Here. Go to the js tab and read the comments. ☺

https://code.sololearn.com/W2o1rIA5I7qQ/?ref=app