#include <iostream> using namespace std; int main() { int p,c,m,err=0; string name; do { try //using try block to check error; { cout<<"Enter sudentname : "; cin>>name; cout<<"Enter physics marks : "; cin>>p; if(!(p>=0 && p<=100)) //checking that marks entered is valid or not; { throw(p); //using throw block to transfer error to catch block; } cout<<"Enter chemistry marks : "; cin>>c; if(!(c>=0 && c<=100)) //checking that marks entered is valid or not; { throw(c); //using throw block to transfer error to catch block; } cout<<"Enter mathsmarks : "; cin>>m; if(!(m>=0 && m<=100)) //checking that marks entered is valid or not; { throw(m); //using throw block to transfer error to catch block; } err=0; //if all the conditions are false then value of error variable is 0 } catch(int e) { cout<<"Invalid Marks"<<endl; //Showing error; err=1; //Changing value of variable to retke input; } }while(err); //it takes input until all inputs are valid; }