Java Use Variable Name to Manipulate Array

Question

Is it possible to use a variable name to manipulate an array?

For example:

String addto = "database";
database = new String[2];

I want to add values into the array named "database", which has only 1 column.

Would it be possible to do something like...

addto[0] = hi;
addto[1] = hi1;

instead of

database[0] = hi;
database[1] = hi1;

etc? Use the value inside "addto" ("database") to manipulate the array?

Thanks!

edit: changed String addto to "database" (with "")

Is the array name, e.g., database, coming from user input, or what? — mellamokb
– mellamokb, Commented Jul 26, 2012 at 17:53
You may look for reflections docs.oracle.com/javase/tutorial/reflect/special/… and java.sun.com/developer/technicalArticles/ALT/Reflection — kosa
– kosa, Commented Jul 26, 2012 at 17:54
How many arrays do you have? Could you manually add them to a Map<string, object[]>, for instance, to link a name to the actual array? — mellamokb
– mellamokb, Commented Jul 26, 2012 at 17:54
Okay why don't you just do String[] addto = database? Is that what you want to do? — user377628
– user377628, Commented Jul 26, 2012 at 18:02

Jon Skeet · Accepted Answer · 2012-07-26 18:00:58Z

5

You'd want to use something like:

Map<String, String[]> arrays = new HashMap<String, String[]>();
arrays.put("database", new String[2]);

...

map.get(addTo)[0] = hi;
map.get(addTo)[1] = hi1;

answered Jul 26, 2012 at 18:00

Jon Skeet

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2 Comments

01jayss Over a year ago

does this create a new array named "database"?

Jon Skeet Over a year ago

@01jayss: No, objects don't have names. It creates a new array, and make that the value associated with the key "database" in a map.

Code-Apprentice · Accepted Answer · 2012-07-26 18:18:43Z

0

String addto = "database"; 
database = new String[2];  
addto[0] = hi;  
addto[1] = hi1;

This code will not compile because addto is a String and does not support indexing with []. To do something similar to this, you can use a java.util.Map as illustrated by Jon Skeet.

answered Jul 26, 2012 at 18:18

Code-Apprentice

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