Flow Control

• Must take a boolean expression.
• You must block the code with "{}" unless there is only one line of code.

• Example of basic if statement:
  if ( boolean )
     System.out.println("True"); //If true do this
  else if
  {  System.out.println("False"); //If false do this
     System.out.println("Code blocks for 2 or more");
  }

• The argument to a switch statement must be a byte, short, int, or char.  Compile error if boolean, long, float, or double.
• The "default:" switch logically should be placed last, however it may be located anywhere.  (see Ex-B )
• Once you have entered a case, you will continue to enter the subsequent cases until you encounter a "break;" statement.  (see Ex-B)
• Braces "{}" start and stop the switch statement.  Do not use braces "{}" to group the statements between the case statements.

• A.  Standard switch statement using an int:
  int myInt = 1;
  switch ( myInt )
  { case 1:
       myInt = 100; break;
    case 2:
       myInt = 200;  break;
    default:
       myInt = 0;
  }
• B.  Example of using the "break;" statement.
  char myChar = 'B';
  switch ( myChar )
  {     
    case 'A':
        System.out.print("A,");
    case 'B':
        System.out.print("B,");
    case 'C':
        System.out.print("C,");
        break;
    case 'D':
        System.out.print("D,");
        break;
    default:
        System.out.println("Default,");
        break;
  }
  Note:  Output = "B, C,"

• need to complete....

Syntax:

for (initialization; termination; increment) {
  statement(s)
}
 

Example:

for(int i=1; i<11; i++){
  System.out.println("Count is: " + i);
}


 

• Must take a boolean expression.  
• Enters express if boolean expression is true.  Continues to loop until boolean expression is false.
• You must block the code with "{}" unless there is only one line of code.
• break - breaks out of the loop.

Examples:

• Example A. 
  x = 0;
  while ( x < 10 ) {
    x++;
  }
• Example B.
  blnContinue = true;
  x = 0;
  while ( blnContinue ) {
    x++;
    if ( x == 5 ) blnContinue = false;
  }
• Example C. (using break)
  x = 0;
  while ( true ) {
    x++;
    if ( x == 5 ) break;
  }

• Must take a boolean expression.  
• Always enters the do loop the first time.  Continues to loop until boolean expression is false.
• You must block the code with "{}" unless there is only one line of code.
• break - breaks out of the loop.

Examples:

• Example A:
  x = 0;
  do {
    x++;
  } while ( x < 10 );
• Example B: (using break)
  x = 0;
  do {
    x++;
    if ( x < 10 ) break;
  } while ( true );