Flow of Control

• The flow of control is the order in which statements in the program are executed.
• All of our programs to this point have had a linear flow of control.
  • The order the statements are written in the code is the order in which they are executed.

    
     cout << "Enter a value =>";
     cin >> i
     cout << "The value is " <<  i <<  endl;
     iSquared = i*i;
     cout << "The value squared is " <<  iSquared <<  endl;
     

  • Line 1 is executed
  • Then line 2
  • Then line 3
  • Then line 4
  • Then line 5
  • Then the program stops.
• In this chapter, and the next four we will learn how to change the flow of control.
• To do this, we will learn control structures
• A control structure is a statement which alters the normal sequential flow of control.
• We will learn two types of control structures
  • Selection : if, if else, case in chapters 5, 7
  • Loops: while, for, do while in chapters 6, 7
• Functions, chapters 8-9 also alter the flow of control in a program.
• Code blocks
  • { } remember!
  • We use code blocks to turn multiple statements into a single statement.
  • We will use code blocks with control structures.
  • There may be times when code blocks are optional with control structures ...
  • But we will almost always include them.
  • And we WILL INDENT inside a code block.