Java Code Manipulation Terms

How do you instantiate an array?
- type Brackets arrayName = elments
- String [] myList = {name1, name2, name3, ......}
- char [] myChar = myList.toArray();
What does the method .toCharArray() do?

It splits up a String [i] into individual characters to break up in information stored in myList[j]
What is a HashMap?

It is a collection of elements stored by a set of keys to values.
How do you access an element stored in a HashMap?

myMap.get("key");
How do you add an element to a Map?

myMap.put("key", new TYPE (values));
How do you display all the keys in a map?
- Iterator i = set.iterator();
- while(i.hasNext()) {
- Map.Entry me = (Map.Entry)i.next();
- System.out.print(me.getKey() + ": ");
- System.out.println(me.getValue());
- }
How do you pick a random key from a Map and display it?
- {Object[] pick = cardMap.keySet().toArray();
- Object key = pick[new Random().nextInt(pick.length)];
- System.out.println("* Random Value * \n" + key); System.out.println();}
What does the .keySet() method do?

It returns a set of keys from a HashMap, which is un-ordered.
What does the .toArray() method do?

it takes any ArrayList or HashMap and turns it into an array of fixed length.
How do I sort through an array?

use Collections.sort
How do I use the .toArray() method?
Take any List or Map and:
- List<T> list = new ArrayList<T>();
- T [] countries = list.toArray(new T[list.size()]);

Author

DLeck17

260353

Card Set

Java Code Manipulation Terms

Description

These are terms that are used manipulating strings and object in Arrays and Maps

Updated

2014-02-05T15:08:50Z