LabelValue Class in JavaTuples

A LabelValue is a Tuple from JavaTuples library that deals with only 2 elements – a label and a value. Since this LabelValue is a generic class, it can hold any type of value in it.

Since LabelValue is a Tuple, hence it also has all the characteristics of JavaTuples: 

• They are Typesafe
• They are Immutable
• They are Iterable
• They are Serializable
• They are Comparable (implements Comparable<Tuple>)
• They implement equals() and hashCode()
• They also implement toString()

Class Declaration

public final class LabelValue<A, B> extends Tuple 
           implements IValueLabel<A>, IValueValue<B> 

Class hierarchy 

Object
  ↳ org.javatuples.Tuple
      ↳ org.javatuples.LabelValue<A, B> 

Creating LabelValue Tuple 

• From Constructor:
  Syntax: 

LabelValue<A, B> kv = new LabelValue<A, B>(value1, value2);

• Example: 

Output: 

[1, Lazyroar]

• Using with() method: The with() method is a function provided by the JavaTuples library, to instantiate the object with such values.
  Syntax: 

LabelValue<type1, type2> kv = LabelValue.with(value1, value2);

• Example: 

Output: 

[1, Lazyroar]

• From other collections: The fromCollection() method is used to create a Tuple from a collection, and fromArray() method is used to create from an array. The collection/array must have the same type as of the Tuple and the number of values in the collection/array must match the Tuple class.
  Syntax: 

LabelValue<type1, type2> kv = LabelValue.fromCollection(collectionWith_2_value);
LabelValue<type1, type2> kv = LabelValue.fromArray(arrayWith_2_value);

• Example: 

Output: 

[Lazyroar, A computer portal]
[Lazyroar, A computer portal]

Getting Value

The getValue() and getLabel() methods can be used to fetch the value and key respectively in a LabelValue Tuple. 

• getLabel():
  Syntax: 

LabelValue<type1, type2> kv = 
    new LabelValue<type1, type2>(value1, value2);

type2 val1 = kv.getLabel();

• Example: 

Output: 

1

• getValue():
  Syntax: 

LabelValue<type1, type2> kv = 
    new LabelValue<type1, type2>(value1, value2);

type2 val1 = kv.getValue();

• Example: 

Output: 

Lazyroar

Setting LabelValue Value

Since the Tuples are immutable, it means that modifying a value at an index is not possible. Hence, JavaTuples offer setLabel(value) and setValue(value) which creates a copy of the LabelValue with a new value according to method used, and returns a new LabelValue object.

• setLabel():
  Syntax: 

LabelValue<type1, type2> kv = 
    new LabelValue<type1, type2>(value1, value2);

LabelValue<type1, type2> kvNew = kv.setLabel(valueNew);

• Example: 

Output: 

[10, Lazyroar]

• setValue():
  Syntax: 

LabelValue<type1, type2> kv = 
    new LabelValue<type1, type2>(value1, value2);

LabelValue<type1, type2> kvNew = kv.setValue(valueNew);

• Example: 

Output: 

[1, A computer science portal]

Searching in LabelValue

An element can be searched in a tuple with the pre-defined method contains(). It returns a boolean value whether the value is present or not.

Syntax:

LabelValue<type1, type2> kv = 
    new LabelValue<type1, type2>(value1, value2);

boolean res = kv.contains(value2);

Example:

Output:

true
false

Iterating through LabelValue

Since LabelValue implement the Iterable<Object> interface. It means that they can be iterated in the same way as collections or arrays.

Syntax:

LabelValue<type1, type2> kv = 
    new LabelValue<type1, type2>(value1, value2);

for (Object item : kv) {
        ...
}

Example:

Output:

1
Lazyroar