What is the Java equivalent of $var?

Question

I'm new to Java and had a newbie question. I am trying to randomly retrieve an enum value as below.

public enum ParkedCar {
     car1(....),
     car2(....);
......
}

Random rand = new Random();
int i = 1 + rand.nextInt(5);
String s = "car" + i;
ParkedCar car = ParkedCar.$s;

However, unlike in Perl where we can use $s to insert the value of s, $s is not valid in Java. What is the Java equivalent if one exists?

Thanks!

ParkerCard.values() will give you array. You may get i-th value of the array. — , Jan 05 '13 at 02:08
Do you mean the car members are not fixed ? It's impossible to implement in Java. The Enum members must be predefined. — Gavin Xiong, Jan 05 '13 at 02:09
possible duplicate of [Convert from enum ordinal to enum type](http://stackoverflow.com/questions/609860/convert-from-enum-ordinal-to-enum-type) — Miserable Variable, Jan 05 '13 at 02:16

score 4 · Answer 1 · answered Jan 05 '13 at 02:18

4

You want Enum.valueOf(String s):

String s = "car" + i;
ParkedCar car = ParkedCar.valueOf(s);

This looks up the enum instance by its name.

Note that if a matching instance isn't found this method will throw a IllegalArgumentException

answered Jan 05 '13 at 02:18

Bohemian

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score 0 · Answer 2 · answered Jan 05 '13 at 02:13

Java is very different than Perl.

You can't build a variable name with a string and then reference it.

(You actually can do it with reflection, but that makes zero sense here)

You can get a random enum value like this:

Random rand = new Random();
ParkedCar[] carArray = ParkedCar.values();
int index = rand.nextInt(carArray.length);
ParkedCar randomCar = carArray[index];

score 0 · Answer 3 · answered Jan 05 '13 at 02:18

0

try: ParkedCar c=ParkedCar.values()[new Random().nextInt(ParkedCar.values().length)];

answered Jan 05 '13 at 02:18

Ray Tayek

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What is the Java equivalent of $var?

3 Answers3