如何使用Switch案例在Java中

Question

I am using Neatbeans 7.0 for Java programming. I have written a Switch case for selection of the program.

switch(menu)
        {
            case 1:
            {
                //stmt
            }
            default:
            {
                //stmt
                return;
            }
        }

I am getting compile time error at switch(menu)

The Error is "strings in switch are not supported in -source 1.6
  (use -source 7 or higher to enable strings in switch)

(Alt-Enter shows hints)" Can any one please help me on this.

Answer 1

String cases in switch statements are supported in Java SE 7 , but not in previous versions of Java. You need to compile with Java 7.

Answer 2

Type of menu is String in your code. If you've JDK 1.6 then switch expression type should be int or char.

You need to change project properties :

1. Source : Source/Binary format : JDK7
2. Libraries : JDK1.7

Answer 3

I'm assuming here that menu is a string type, though it doesn't really match your case statements. Allowing the use of strings in switch statements was added in Java 7.

You can either switch to Java 7 and fix the case so that it checks against a string rather that the integral 1 , or convert menu to an integer and check that, such as with Integer.ParseInt() , something like:

String menu = "1";
int menuint;
try {
    menuint = Integer.ParseInt (menu);
} catch (NumberFormatException e) {
    menuint = -1;
}
switch (menuint) {
   :

Answer 4

A switch works with the byte, short, char, and int primitive data types.

String is unsupported until Java-6. Java 7 supports String object in switch-case.

In Java SE 7 and later, you can use a String object in the switch statement's expression.

Read more here: http://docs.oracle.com/javase/tutorial/java/nutsandbolts/switch.html

Answer 5

I think it should be:

case "1":

....