Program-22
Aim:-     Write a program to perform the deletion of whitespaces such as horizontal tabs,
vertical tabs, space, line feed, new line and carriage return from a text file and store the
contents of the file without the white spaceson another file.
Program :-
      #include <iostream>
      #include<fstream>
      using namespace std;
      int main(){
      ifstream prev("according_8_1.txt"); ofstream next("according_8_2.txt"); char ch;
      int c = prev.peek(); while(!prev.eof())
      {
      ch= prev.get();
      if(ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r' || ch == '\f' || ch == '\v'||ch=='\0'){} else{
      next.put(ch);
      }
      c = prev.peek();
      }
      cout << "Program Executed" << endl; return 0;
}
                                        Program-23
Aim:- Write a program to read the class object of student_info such as name, age, sex, height
and weight from the keyboard and to store them on a specified file using read() and write()
functions. Again, the same file is opened for reading and displaying the contents of the file on
the screen.
Program :-
      #include <iostream>
      #include <fstream>
      using namespace std;
      class student_info{ public:
      string name, age, height, weight; char sex;
      void read(); string write();
      };
      void student_info :: read(){ cout << "Enter Name: "; cin >> name;
      cout << "Enter Age: "; cin >> age;
      cout << "Enter Gender(F/M): "; cin >> sex;
      cout << "Enter Height: "; cin >> height;
      cout << "Enter Weight(kilogram): "; cin >> weight;
      }
      string student_info :: write(){
      return "Name: " + name + "\n" + "Age: " + age + "\n" + "Gender: " + sex + "\n" +
      "Height: " + height + "\n" + "Weight: " + weight + "\n" + "\n";
      }
      int main(){
      int n;
      cout << "Enter how many records are to be stored: "; cin >> n;
      student_info student[n]; ofstream output;
      output.open("according_9.txt", ios::app);
      // output.write()
      for (int i = 0; i < n; i++){ student[i].read();
      // output.write(student, sizeof(student[i])); output << student[i].write();
    }
    output.close(); ifstream fin;
    cout << "..............DISPLAYING THE CONTENTS OF THE FILE.   " << endl;
    fin.open("according_9.txt"); string input;
    for(int i = 0; i < n; i++){ while(getline(fin, input)){
    cout << input << endl;
    }
    }
    fin.close(); return 0;
}
                                       Program-24
Aim:- Write a program to raise an exception if any attempt is made to refer an element
whose index is beyond the array size.
Program :-
#include <iostream>
using namespace std;
void array_value(int i, int n, int *array){ if(i > n){
throw out_of_range("The entered index is out of range of the array!\n");
}
cout << "The value in the array at the index " << i << " is " << array[i] << endl;
}
int main(){ int n;
cout << "Enter the size of the array: "; cin >> n;
int *array = new int[n];
cout << "Enter the elements: \n"; for(int i = 0; i < n; i ++){
cin >> array[i];
}
bool running = true; while(running){
int i;
cout << "Enter the index of element you want to access: "; cin >> i;
try{
array_value(i, n, array);
}
catch(out_of_range &e){
cout << "Exception occured: " << e.what();
}
char choice;
cout << "Do you want to get any other element(y/n): "; cin >> choice;
if(choice == 'n'){ running = false;
}
else if(choice != 'y' && choice != 'n'){ cout << "Wrong choice entered!\n";
}
}
return 0;
}
                                       Program-25
Aim:- Write a program to read a set of lines from the keyboard and to store it on a
specified file.
Program :-
   #include <iostream>
   #include <fstream>
   using namespace std;
   int main(){ string input;
   ofstream output("beyond_18.txt");
   cout << "Enter the lines you want to add in the file:\nEnter 'end' when you want to stop!\n";
   do{
   getline(cin, input); if(input != "end"){ output << input; output << "\n";
   }
   }while(input != "end"); return 0;
   }
                                         Program-26
    Aim:-   Write a program to read a text file and display its contents on the screen
    Program :-
     #include <iostream>
     #include <fstream>
     using namespace std;
     int main(){ string input;
     ifstream in("beyond_19.txt"); while(getline(in, input)){
     cout << input << endl;
     }
     In.close(); return 0;
}
                                      Program-27
Aim:- Write a program to copy the contents of a file into another.
Program :-
     #include <iostream>
     #include <fstream>
     using namespace std;
     int main(){ string input;
     ifstream source("beyond_20_1.txt"); ofstream destination("beyond_20_2.txt");
     cout << "Copying files from beyond_20_1.txt to beyond_20_2.txt\n";
     while(getline(source, input))
     {
     cout << input << endl; destination << input; destination << "\n";
     }
     source.close(); destination.close(); return 0;
}
                                      Program-28
Aim:- Write a program to read two numbers and divide the first number by the second
number and raise anexception if the second number is zero.
Program :-
   #include <iostream>
   using namespace std;
   float divide(float n1, float n2){ if(n2 == 0){
   throw runtime_error("Cannot divide by 0!\n");
   }
   return (n1 / n2);
   }
   int main(){ float n1, n2;
   cout << "Enter two numbers: "; cin >> n1 >> n2;
   try{
   float result = divide(n1, n2);
   cout << n1 << " divided by " << n2 << " is " << result << endl;
   }
   catch(runtime_error &error){
   cout << "Exception occured: " << error.what();
   }
   return 0;
   }