Controlling the Flow of Your Program - Beginning Java Programming: The Object-Oriented Approach - page 163

if (emp.equals(employeeID)){
return true;
}
}
return false;
}
As soon as the specified employeeID is found, the Boolean true will be returned. This will interrupt
the search, whether it is the first string in the array, the last string, or anywhere in between. In this
way, the flow of the program is controlled by the return statement.
It is also possible to use the return statement in the same way, but with a void method. In this case,
the method will be interrupted, but no value will be returned.
import java.util.ArrayList;
static ArrayList<String> employeeList = new ArrayList< >();
//a method to add new Employees to the Employee array
static void addNewEmployee(String employeeID){
if (employeeList.contains(employeeID)){
return; //employee already exists
}
employeeList.add(employeeID);
}
In this example, if the employee is found in the ArrayList , then there is no need to put her into it.
Therefore, the code returns nothing as soon as the employee is found and then exits the method.
Controlling with the break Keyword
The break keyword also interrupts the execution of the current block of code. You already saw
this keyword used as part of the switch statement. It can also be used, in a similar way, with loop
structures. A break could be thought of as a softer interruption than return , as the method con-
tinues to execute, just in a different place after breaking out of the current block. If break occurs
as part of an iterative loop, the loop containing the break statement will be stopped and it will
not complete any further iterations. In the following example, the use of the break keyword to
exit a loop is shown.
//array of employee ID numbers, stored as Strings
static String[] employees;
//method to search for a specified employee ID
static void findEmployee(String employeeID){
String myString = employeeID + " was not found.";
for (String emp : employees){
if (emp.equals(employeeID)){
myString = employeeID + " was found.";
break;
}
}
System.out.println(myString);
}