Why is pointer not updating the variable?

Question

This code is giving output '101100'. I want to know why ++*p in 'cout' statement not updating the value of 'a' in the program.
When I write '++*p' outside the 'cout' it updates the variable 'a'.
I have also tried this code in c and it gives the same output.

https://code.sololearn.com/c8nr9k9ZGCt0/?ref=app

Answer 1

cout>>++*p >> *p;

++*p ==> another word: *p=*p+1

it will not implement assign operator ultil meet ';'
Because assign operator is valid after ';'.

the result of pression (++*p) is as same as (*p+1).
*p value can't change before ';'

Try this code to understand:

#include <iostream>
using namespace std;

int main()
{
int a=10;
int *p=&a;
cout<<++*p<<*p;
cout<<*p;
return 0;
}

//result: 11 10 11

Answer 2

it is updating.

using multiple << with ++ and cout it acts strange

use two cout statements and you will see it is correct

cout<<++*p;
cout<<*p;
😆

Answer 3

@jay thanks for that but I want to know what happens when I write it together.Why doesn't the *p prints updated value?