a=b++, a=++b what different between it....?

Answer 1

The difference between prefix and postfix forms of incremental/decremental operators is in order of operations.
b = 5;
a = ++b; // a = 6, b = 6
Firstly, b is increased by 1, after that its value is assigned to a.
a = b++; // a = 6, b = 7
b value is assigned to a variable, then b will be increased by 1.

Answer 2

this question has been asked multiple multiple times. use search bar.
https://www.sololearn.com/discuss/1316935/?ref=app
https://www.sololearn.com/post/10362/?ref=app