Let's say I have a class myClass and a String myString. How would I do this:
myClass [value of myString] = new myClass;
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1Using a string value as a variable? You can't. Is there a reason why you want to do this?Lews Therin– Lews Therin2013-03-27 22:50:29 +00:00Commented Mar 27, 2013 at 22:50
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4 Answers
You can't have a dynamic variable in Java. Still, you can use a Map<String, Object> to have the String myString as the key and set the new value as new instance of your class:
Map<String, Object> map = new HashMap<String, Object>();
map.put(myString, new MyClass());
If you're sure your map will only contain MyClass instances, then you can use Map<String, MyClass>.
Map<String, MyClass> map = new HashMap<String, MyClass>();
Comments
You cannot use the value of a string variable as a variable name. Java doesn't allow that.
However, with a Map, you can associate a string (as a key) to a value:
Map<String, MyClass> map = new HashMap<String, MyClass>();
map.put(myString, new MyClass());
It's not exactly what you're looking for, but in Java, that's as close as you're going to get.
3 Comments
Luiggi Mendoza
looks like we have the same idea and took the same time to write our answers.
Armen Tsirunyan
How is strong typing relevant? It's more about compile-time naming :)
rgettman
@Armen, I don't think strong typing has anything to do with it. The Java compiler expects variable identifier names to have a name directly in the source file at compile time, and the identifier is not reliant, and cannot be reliant, on any runtime value such as the value of
myString.Use a map to store your Objects indexed by your String
public static void main(String[] args) {
final String myString = "something";
final Map<String, Object> map = new HashMap<String, Object>();
map.put(myString, new Object());
}
answered Mar 27, 2013 at 22:52
Boris the Spider
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Comments
what about using generics and creating a base class with type parameters
public MyGenClass<K,V>{
private Map<K,V> map = new HashMap<K,v>();
public Map<K,V> getMap(){
return map;
}
public void setMap(Map<K,V> iMap){
map=iMap;
}
}
using this class, you can easily get different kind of maps while having similar methods.
enjoy :)
