A Quartet is a Tuple from JavaTuples library that deals with 4 elements. Since this Quartet is a generic class, it can hold any type of value in it.
Since Quartet 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 Quartet<A, B, C, D> extends Tuple
implements IValue0<A>, IValue1<B>, IValue2<C>, IValue3<D>

Class hierarchy

Object
  ↳ org.javatuples.Tuple
      ↳ org.javatuples.Quartet<A, B, C, D>

Creating Quartet Tuple

• From Constructor:
  Syntax: 
   

Quartet<A, B, C, D> quartet = 
    new Quartet<A, B, C, D>
        (value1, value2, value3, value4);

• Example: 
   

• Output: 
   

[1, GeeksforGeeks, A computer portal, 20.18]

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

Quartet<type1, type2, type3, type4> quartet = 
    Quartet.with(value1, value2, value3, value4);

• Example: 
   

• Output: 
   

[1, GeeksforGeeks, A computer portal, 20.18]

•  
• 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: 
   

Quartet<type1, type2, type3, type4> quartet = 
    Quartet.fromCollection(collectionWith_2_value);

Quartet<type1, type2, type3, type4> quartet = 
    Quartet.fromArray(arrayWith_2_value);

• Example: 
   

• Output: 
   

[GeeksforGeeks, A computer portal, for geeks, by Sandeep Jain]
[GeeksforGeeks, A computer portal, for geeks, by Sandeep Jain]

Getting Value

The getValueX() method can be used to fetch the value in a Tuple at index X. The indexing in Tuples starts with 0. Hence the value at index X represents the value at position X+1.
Syntax: 
 

Quartet<type1, type2, type3, type4> quartet = 
    new Quartet<type1, type2, type3, type4>(value1, value2, value3, value4);

type1 val1 = quartet.getValue0();

Example: 
 

Output: 
 

1
A computer portal

Setting Quartet Value

Since the Tuples are immutable, it means that modifying a value at any index is not possible. Hence, JavaTuples offer setAtX(value) which creates a copy of the Tuple with a new value at index X, and returns that Tuple.
Syntax: 
 

Quartet<type1, type2, type3, type4> quartet = 
    new Quartet<type1, type2, type3, type4>
                (value1, value2, value3, value4);

Quartet<type1, type2, type3, type4> 
    otherQuartet = quartet.setAtX(value);

Example: 
 

Output: 
 

[1, GeeksforGeeks, A computer portal, 2.018]

Adding a Value

Adding a value can be done with the help of addAtX() method, where X represent the index at which the value is to be added. This method returns a Tuple of element one more than the called Tuple.
Syntax: 
 

Quartet<type1, type2, type3, type4> quartet = 
    new Quartet<type1, type2, type3, type4>
        (value1, value2, value3, value4);

Quintet<type 1, type 2, type 3, type 4, type 5> quintet = 
    quartet.addAtx(value);

Example: 
 

Output: 
 

[1, GeeksforGeeks, A computer portal, for geeks, 20.18, true]

Searching in Quartet

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: 
 

Quartet<type1, type2, type3, type4> quartet = 
    new Quartet<type1, type2, type3, type4>(value1, value2, value3, value4);

boolean res = quartet.contains(value2);

Example: 
 

Output: 
 

true
false

Iterating through Quartet

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

Quartet<type1, type2, type3, type4> quartet = 
    new Quartet<type1, type2, type3, type4>
            (value1, value2, value3, value4);

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

Example: 
 

Output: 
 

1
GeeksforGeeks
A computer portal
20.18

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready.