LabelValue Class in JavaTuples

Last Updated : 27 Aug, 2018

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 characterstics 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:

// Below is a Java program to create
// a LabelValue tuple from Constructor
  
import java.util.*;
import org.javatuples.LabelValue;
  
class GfG {
    public static void main(String[] args)
    {
        LabelValue<Integer, String> kv
            = new LabelValue<Integer, String>(Integer.valueOf(1),
                                              "GeeksforGeeks");
  
        System.out.println(kv);
    }
}

Output:

[1, GeeksforGeeks]

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:

// Below is a Java program to create
// a LabelValue tuple from with() method
  
import java.util.*;
import org.javatuples.LabelValue;
  
class GfG {
    public static void main(String[] args)
    {
        LabelValue<Integer, String> kv
            = LabelValue.with(Integer.valueOf(1), "GeeksforGeeks");
  
        System.out.println(kv);
    }
}

Output:

[1, GeeksforGeeks]

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:

// Below is a Java program to create
// a LabelValue tuple from Collection
  
import java.util.*;
import org.javatuples.LabelValue;
  
class GfG {
    public static void main(String[] args)
    {
        // Creating LabelValue from List
        List<String> list = new ArrayList<String>();
        list.add("GeeksforGeeks");
        list.add("A computer portal");
        LabelValue<String, String> kv
            = LabelValue.fromCollection(list);
  
        // Creating LabelValue from Array
        String[] arr = { "GeeksforGeeks", "A computer portal" };
        LabelValue<String, String> otherLabelValue
            = LabelValue.fromArray(arr);
  
        System.out.println(kv);
        System.out.println(otherLabelValue);
    }
}

Output:

[GeeksforGeeks, A computer portal]
[GeeksforGeeks, 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:

// Below is a Java program to get
// a LabelValue value
  
import java.util.*;
import org.javatuples.LabelValue;
  
class GfG {
    public static void main(String[] args)
    {
        LabelValue<Integer, String> kv
            = LabelValue.with(Integer.valueOf(1), "GeeksforGeeks");
  
        System.out.println(kv.getLabel());
    }
}

Output:

getValue():

Syntax:

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

type2 val1 = kv.getValue();

Example:

// Below is a Java program to get
// a LabelValue value
  
import java.util.*;
import org.javatuples.LabelValue;
  
class GfG {
    public static void main(String[] args)
    {
        LabelValue<Integer, String> kv
            = LabelValue.with(Integer.valueOf(1), "GeeksforGeeks");
  
        System.out.println(kv.getValue());
    }
}

Output:

GeeksforGeeks

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:

// Below is a Java program to set
// a LabelValue Key
  
import java.util.*;
import org.javatuples.LabelValue;
  
class GfG {
    public static void main(String[] args)
    {
        LabelValue<Integer, String> kv
            = LabelValue.with(Integer.valueOf(1), "GeeksforGeeks");
  
        LabelValue<Integer, String> otherLabelValue
            = kv.setLabel(10);
  
        System.out.println(otherLabelValue);
    }
}

Output:

[10, GeeksforGeeks]

setValue():

Syntax:

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

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

Example:

// Below is a Java program to set
// a LabelValue Value
  
import java.util.*;
import org.javatuples.LabelValue;
  
class GfG {
    public static void main(String[] args)
    {
        LabelValue<Integer, String> kv
            = LabelValue.with(Integer.valueOf(1), "GeeksforGeeks");
  
        LabelValue<Integer, String> otherLabelValue
            = kv.setValue("A computer science portal");
  
        System.out.println(otherLabelValue);
    }
}

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:

// Below is a Java program to search
// a value
  
import java.util.*;
import org.javatuples.LabelValue;
  
class GfG {
    public static void main(String[] args)
    {
        LabelValue<Integer, String> kv
            = LabelValue.with(Integer.valueOf(1), "GeeksforGeeks");
  
        // Using contains for True result
        boolean exist = kv.contains("GeeksforGeeks");
  
        // Using contains for False result
        boolean exist1 = kv.contains(4);
  
        System.out.println(exist);
        System.out.println(exist1);
    }
}

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:

// Below is a Java program to iterate
// a LabelValue
  
import java.util.*;
import org.javatuples.LabelValue;
  
class GfG {
    public static void main(String[] args)
    {
        LabelValue<Integer, String> kv
            = LabelValue.with(Integer.valueOf(1), "GeeksforGeeks");
  
        for (Object item : kv)
            System.out.println(item);
    }
}

Output:

1
GeeksforGeeks

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