[Java] Switch on Strings in Java ^_^

[evill33t]

Since you cant switch strings in java..someone made a funny bypass
(found it on worsethanfailure )

int helpArg = getHashValue("help");

int singleArg  = getHashValue("single");

int mutiArg = getHashValue("multi");



public static void  main (String args[])

{

    // Get a hash value for the first argument

    int hash = getHashValue(args[0].toCharArray());



    switch(hash)

    {

        case helpArg: 

            ...

            break;

        case singleArg: 

            ...

            break;

        case mutiArg: 

            ...

            break;

        // etc

    }

}

the orginal version

public static void  main (String args[])
{
    // Get a hash value for the first argument
    int hash = getHashValue(args[0].toCharArray());

    switch(hash)
    {
        case 972346: // The first argument was "help"
            ...
            break;
        case -91058: // The first argument was "single"
            ...
            break;
        case -4830672: // The first argument was "multi"
            ...
            break;
        // etc
    }
}

Attention: Some Strings can have the same hashcode but overall it should be secure to use this

 

[username1]

sage

A series of else if would work just as well, with no chance of collision.

 

[evill33t]

sure it would work but its just an example how to use switch on strings
imagine 100 else conditions then this switch would look nicer
and it would work faster (the hash function takes up the speed you gain tough)

edit:
i wouldnt use it in a real project
its just a funny code snippet

 

[username1]

If all your strings are 4 or less characters in length, this is one way to switch (32-bit machine):

char strarray[4];
unsigned int *dordmaker = &strarray;
switch(*dordmaker) {
 case 542393671:
  ...
 case 1414745936:
  ...
 case 1145128264:
  ...
}

This gets even better on a 64-bit machine. 8 or less characters in length. Or you could use long ints on a 32-bit machine.