Switch Statement in Java
Beginning with JDK 7, we can use a string literal/constant to control a switch statement, which is not possible in C/C++. Using a string-based switch is an improvement over using the equivalent sequence of if/else statements.
Important Points:
Expensive operation: Switching on strings can be more expensive in term of execution than switching on primitive data types. Therefore, it is best to switch on strings only in cases in which the controlling data is already in string form.
String should not be NULL: Ensure that the expression in any switch statement is not null while working with strings to prevent a NullPointerException from being thrown at run-time.
Case Sensitive Comparison: The switch statement compares the String object in its expression with the expressions associated with each case label as if it were using the String.equals method; consequently, the comparison of String objects in switch statements is case sensitive.
Better than if-else: The Java compiler generates generally more efficient bytecode from switch statements that use String objects than from chained if-then-else statements.
// Java program to demonstrate use of a
// string to control a switch statement.
public class Test
{
public static void main(String[] args)
{
String str = "two";
switch(str)
{
case "one":
System.out.println("one");
break;
case "two":
System.out.println("two");
break;
case "three":
System.out.println("three");
break;
default:
System.out.println("no match");
}
}
}
Output:
two