The If Statement

• two new reserved words if, else

  if (condition) statement;
  
  if (condition) 
      statement;
  
  if (condition) 
      statement1
  else
      statement2;
  
  
  if (condition) {
      statements A;
  } else {
      statements B;
  }
      

• Indentation indentation indentation
• Write a program that reads in two numnber and prints out the bigger
• Write a program that reads in a final score and prints out a letter grade.
• It is possible to nest if then else statements

  if (condition1) {
     if (condition2) {
        statement 1
     } else {
        statement 2
     }
  } else {
     if (condition3) {
        statement 3
     } else {
        statement 4
     }
  }
  
  if (condition 1 ) {
      statement 1
  } else if (condition 2) {
      statement 2
  } else if condition 3) {
      statement 3
  } else {
      statement 4
  }
      

• Write a program that reads in three numbers and prints out the bigger
• Write a program to find the number of real roots for a given quadratic equation
• Write a program to print the real roots of a given quadratic equation.
• Testing the input stream
  • A stream object returns true if the last operation was successful and false if the last operation was a failure.

    ifstream infile;
    
    infile.open("hello.dat");
    if (!infile) {
       cout << "Failed to open the input file hello.dat" << endl;
       return -1;
    } else {
       infile >> anInt;
       if (!infile) {
          cout << "Failed to read an integer from hello.dat" << endl;
          return -1;
       }
       return 0;
    }
    	

• Do program 5 page 247
• Do program 7 page 247
• Do program 8 page 247