I'm a newbie in Java who used PHP before that. I want to define an array in Java with a key for each array entry like in PHP. For example, in PHP I would have this:
$my_arr = array('one'=>1, 'two'=>2, 'three'=>3);
How would I define this array in Java?
In Java, array indices are always of type int. What you are looking for is a Map. You can do it like this:
Map<String,Integer> map = new HashMap<>();
map.put("one", 1);
map.put("two", 2);
map.put("three", 3);
Code:
import java.util.*;
public class HashMapExample
{
public static void main (String[] args)
{
Map<String,Integer> map = new HashMap<>();
map.put("one", 1);
map.put("two", 2);
map.put("three", 3);
//how to traverse a map with Iterator
Iterator<String> keySetIterator = map.keySet().iterator();
while(keySetIterator.hasNext()){
String key = keySetIterator.next();
System.out.println("key: " + key + " value: " + map.get(key));
}
}
}
Output:
key: one value: 1
key: two value: 2
key: three value: 3
Source: For reading more take a look at this source
Tutorial for Itrators
2.http://www.java-samples.com/showtutorial.php?tutorialid=235
.iterator() and keySetIterator.next() for this HashMap
What you need is a Map implementation, like HashMap.
Take a look on this tutorial, or the official Java tutorial for further details.
You can't do this with simple arrays with Java, simply because arrays are just simply containers.
Thankfully, there's a class that you can use that does exactly what you want:
http://docs.oracle.com/javase/7/docs/api/java/util/HashMap.html
For some tutorial, read : http://www.tutorialspoint.com/java/java_hashmap_class.htm
