i have declared a variable as
uint32_t num;
when i take input for this variable i.e
cin>>num;
cout<<num<<endl;
& take its cout, then it gives problem.

when i run this program, i gives num value as 12345678, it works fine & give cout. but when i give input as 1234abcd. it creates problem & displays only 1234.
please suggest solution to resolve this problem.

Thats because uint3_t can only hold numbers. What you want is strings.

#include <iostream>
#include <string>
using namespace std;

int main(){
 string input;
 cout << "Enter something : ";
 cin >> input;
 cout << "You entered : " << input << endl;
 return 0;
}