++a?

Question

How work
Int a =10, b;
b = ++a+a;
cout << b;
I don't remember lessons about ++a, only a++.

Answer 1

int a=10;

cout<< ++a + a<<endl; // 11+11=22, increments value first then uses it value next,
cout<<a; //11

a=10;

cout<< a++ + a <<endl; //10+11=21 , first it's value uses in print and increments next.
cout<<a; //11

edit:
if there is sequence point issue, then output is compiler dependent because output is undefined by standards.

Answer 2

++a means that value of a is changed by one before rest of the line runs. Your code means the same as
int a=10,b;
a++;
b=a+a;
cout<<b;

Answer 3

It is in this lesson
https://www.sololearn.com/learning/1610/

Answer 4

Sorry, don't understand