Java Language Fundamentals 719
BD4
switch(numberOfSiblings) {
case 0:
System.out.println(“An only child, I see.”);
break;
case 1:
System.out.println(“The typical family!”);
break;
case 2:
System.out.println(“Three kids can be a handful.”);
break;
default:
System.out.println(“It must have been crowded at your house!.”);
}
Suppose the breakstatement were omitted from the case 0:block. Then, when the
expression is equal to 0 , the code under case 0:would be executed followed by the
code under case 1:. In other words, when switchfinds a match, it starts executing code
at the matching casestatement and continues until it finds a breakstatement or reaches
the end of the switchconstruct. Again, this functionality matches C and C++.
for................................................................................................................
Theforconstruct is used to execute a block of statements a specified number of times.
The syntax is
for (variable= initial value; expression1; expression2)
{
statementblock;
}
variableis any numeric variable, and expression1is a Boolean (true/false) expression.
Here’s how a forconstruct works when execution reaches it:
1.variableis set equal to initial value.
2.expression1is evaluated. If true,statementblockis executed. If false, exit the
forconstruct.
- Evaluate expression2.
- Return to step 2.
Most frequently, the forconstruct is used to “count” from one value to another. This
loop counts up from 0 to 100 and displays the values on the screen:
for (i = 0; i < 101; i++)
{
System.out.println(i);
}
39 448201x-Bonus4 8/13/02 11:19 AM Page 719