switch « string « Java Data Type Q&A

1. Switch Statement with Strings in Java    stackoverflow.com

Why can't I switch on a String in Java? Is this functionality going to be put into a later Java version? Can someone point me to an article, or themselves explain why I ...

2. using switch in strings    stackoverflow.com

Trying to use switch in strings by first coverting string into char and then apply switch but still didnt done it....here is my code..

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import javax.swing.JOptionPane;

class HappyBirthday {


3. Changing if else to switch for string    stackoverflow.com

How can I write the following method using switch case instead of if else

public void startElement(String uri, String localName, String qName,
    Attributes attributes) throws SAXException 


4. using switch block in java instead of multiple if statements    stackoverflow.com

public class A {
  public void search(boolean[] searchList) {
    // searchList array is used to identify what options to search for in a given order

5. Is there a more object oriented method for selecting a class based on a string than using if-else statements (or switch)?    stackoverflow.com

I have a system where I receive a string from an outside library, and need to select a specific class based on that string. Unfortunately, I have no control over the ...

6. Java SE 7 installed, but string in switch not supported    stackoverflow.com

I've recently installed Java SE 7 on my Ubuntu and tried to compile code with switch on string but couldn't do that. I compiled from command-line. Why?

java -version
java version "1.7.0"
Java(TM) SE ...

7. Java 7 String switch decompiled: unexpected instruction    stackoverflow.com

I have decompiled a very simple class that uses the new Java 7 String Switch feature. The class:

public class StringSwitch {

    public static void main(String[] args) {


8. String in switch java    stackoverflow.com

    case "Return":
strings ...

9. Unable to switch on String in JRE7    stackoverflow.com

I'm on jre7 and I still can't switch on Strings. I installed jdk7 update 1 and pointed Eclipse to it but still no luck. Any idea what I'm doing wrong? Thank ...

10. Use of strings in "switch" statement; Java SE 7    stackoverflow.com

I wanted to use a String in a switch statement but I read that this feature was available from version java SE 7. I've downloaded it, when I type "java -version" ...

11. Switch Statement and a String    coderanch.com

Here is what I have done to select a case according to a String. You have to set up a Hashtable where each key is a String you want recognized, and the object stored is an Integer that has a unique numeric value. Then you can just switch( ((Integer)table.get( keystring )).intValue() ) Bill

12. switch with Strings    coderanch.com

It's quite easy to mimic the 'switch' semantics in a polymorphic way. Construct a map an populate it with the key objects represent the 'case selectors' and associate the value part of the tuples with 'Actor' interfaces: public interface Actor { public void exectute(); } Given a selector (used in the 'switch()' clause), look it up in the map; if an ...

13. argh! why can't a switch selector be a string!    coderanch.com

If you look at the JVM Spec, there's an instruction called tableswitch which is how switch statements typically get implemented. It's a fast way of getting to a particular spot in your code based on the switch value, without doing a lot of comparisons. (It also takes more memory than multiple comparisons would, but that's usually considered a fair trade.) This ...

14. switch on a string?    coderanch.com

If they are single character strings, you could use CHAR although thats rare. Usually I assign a "public static final int" for each type of output I expect, basically defining a category, then use this inside my switch statements. There is still the problem of if a user inputs a string and you need to convert it to int although you ...

15. switch on a string    coderanch.com

The Java Language Specification just states that the value of the switch expression must be char, byte, short, int, Character, Byte, Short, Integer, or an enum type, or a compile-time error occurs. It does not exaplin why it does not accept Strings in the switch statement. Then it is one of those things other languages have and Java simply does not. ...

16. you cant switch a String?    coderanch.com

ok, i used if else, but i have to look at input and decide if its a "special command" or not, then execute that special command. Example: #logoff #sethost #setport etc... i am extracting the input, and using substring to get the names and seeing if its a command.. any easier way? Justin

17. switch statement on String    coderanch.com

Being able to switch on a String is a proposed feature of Java 7 due out in early 2010. Assuming waiting until then is not an option there's a couple of things you could do. The thing I would ask is what is going to be the contents of the conditional block? Is there a lot of logic in it? If ...

18. switch on String    coderanch.com

19. can we use string in switch    coderanch.com

Hi all, i am using java 1.5. hi Ranch Hand,Hi satish varma String state variety = condition ? "fish" : "fowl"; in this , i do not understand what is state ,what is variety? as of i know both are string objects. i do not think it will execute properly.. i know we can use enum thanks for the link for ...

20. switch by String not possible, so why does Java tutorial say it is?    coderanch.com

In current version of Java, I understand switch by String is not possible (though will be in future version). So why does the current Java tutorial say it is? http://download.oracle.com/javase/tutorial/java/nutsandbolts/switch.html Unlike if-then and if-then-else statements, the switch statement can have a number of possible execution paths. A switch works with the byte, short, char, and int primitive data types. It also ...

21. Using switch with a string    coderanch.com

I have written the following : public static String dnaComplementReverser(String text) { String reverse = ""; for (int i = text.length() - 1; i >= 0; i--) { String c = ""; switch (text.charAt(i)) { case 'A': c = "T"; case 'T': c = "A"; case 'C': c = "G"; case 'G': c = "C"; } reverse = reverse + c; ...

22. switch on a string    java-forums.org

but still, your not garanteed that it will be the right string he selected,isn't it? It would be a nasty bug to track down. there is no possibility other then using else if? Most things in java have the source code in the src.zip file, is the switch statement scripted over there?(which would be strange because switch isn't an object and ...

23. converting string input to use with a switch    forums.oracle.com

I need to convert input from the JOption.Pane.showInputDialog () method. Which is going to be "A" , "B" , "C". and be able to use it in a switch statement. I know the switch statement will only take a char or a int, so how do I convert a string to a char to compare.

24. Switch statement (with strings?)    forums.oracle.com

Good point flounder. Of course if you're going to go on the assumption the user is unrealistically entering massive amounts of wrong answers, or attempting to crash the program on themselves, you would probably want a limit on the amount whether it be a loop or recursion. While a valid point, it's not too realistic. It's only an alternative. In this ...

25. String in Switch statement    forums.oracle.com

The JLS says this: The prohibition against using null as a switch label prevents one from writing code that can never be executed. If the switch expression is of a reference type, such as a boxed primitive type or an enum, a run-time error will occur if the expression evaluates to null at run-time. It follows that if the switch expression ...

26. Java Switch Statement with Strings    forums.oracle.com

It might not be more "efficient", but it's certainly quite readable... Using a map actually will almost certainly be more efficient. Switching through strings would probably require a .equals() comparison for each string int the statement up to the right answer. This linear ( O(n) ) time. Using a treemap takes this down to logarithmic ( O(log n) ) time and ...