Map Class

From Axaptapedia

Map (Foundation class) consist of a data set that contains a key and a corresponding value, where the key is unique. The key and the value need not be from the same data type.

A Map is alway sorted on the key value.

Contents 1 How to use 1.1 Define 1.2 Insert a value 1.3 Exists value 1.4 Getting values 1.4.1 MapIterator 1.4.2 MapEnumerator 1.4.3 Direct method 1.5 Removing values 1.6 Updating values 1.7 Other methods 1.8 Passing across tiers 2 See also

[edit] How to use

[edit] Define

Map m = new Map(Types::STRING, Types::INTEGER);

[edit] Insert a value

m.insert("Wassini", 37);
m.insert("Eric", 102);

[edit] Exists value

To see if a value already is added, use the exists method:

if (m.exists("Wassini"))
   print "Yes!";
else
   print "No!";

[edit] Getting values

There are several ways to get the values in the map.

1. Using a MapIterator
2. Using a direct method

[edit] MapIterator

The MapIterator loops throug the complete map:

MapIterator mi;
 
mi = new MapIterator(m);
 
while (mi.more())
{
  print mi.key();
  print mi.value();
 
  mi.next();
}

[edit] MapEnumerator

MapEnumerator class is like MapIterator class, but allows the deletion of elements during enumeration and MapIterator does not.

MapEnumerator me = m.getEnumerator();
 
while (me.moveNext())
{
  print me.currentKey();
  print me.currentValue();
}

[edit] Direct method

It is possible to get find a specific value from the key:

print m.lookup("Wassini");

[edit] Removing values

Just use the remove method to remove the active key/value pair.

m.remove("Wassini");

[edit] Updating values

It is not possible to update a value directly:

int age;
str keyid = "Wassini";
 
age = m.exists(keyid) ? m.lookup(keyid) : 0;
m.insert(keyid, age + 1);

[edit] Other methods

// Get number of elements:
print m.elements(); 
 
// Get the used types:
print m.definitionString(); 
 
// Dump the whole map as a string:
print m.toString();

[edit] Passing across tiers

As with other foundation classes, the Map can be passed across tiers by converting it to a container. The pack method converts it to a container:

container packedMap = m.pack();

To convert the packed container back to a Map, call the static create method of the Map class:

Map map = Map:create(packedMap);

[edit] See also

• Collection classes