The indexOf() method in org.javatuples is used to find the index of a value, passed as parameter, in TupleClass. This method takes the parameter of Object type, so that it can check for all type of values. It is inherited from the JavaTuple class. This method can be used to any tuple class object of javatuples library. It returns an int which is the first index of the value passed as the parameter, if found. If not found, then it returns -1.
Method Declaration:
public final int indexOf(Object value)
Syntax:
int index = TupleClassObject.indexOf(Object value)
Here TupleClassObject represents the JavaTuple Class object used like Unit, Quintet, Decade, etc.
Return Value: This method returns an int which is the first index of the value passed as the parameter, if found. If not found, then it returns -1.
Below programs illustrate the various ways to use indexOf() method:
Program 1: Using indexOf() with Unit class:
// Below is a Java program to use indexOf() method  import java.util.*;import org.javatuples.Unit;  class GfG {    public static void main(String[] args)    {        // Creating an Unit with one value        Unit<String> unit = Unit.with("Lazyroar");          // Using indexOf() method for present value        int index1 = unit.indexOf("Lazyroar");          // Printing the index1        System.out.println("Index of Lazyroar = "                           + index1);          // Using indexOf() method for absent value        int index2 = unit.indexOf("Present");          // Printing the index2        System.out.println("Index of Present = "                           + index2);    }} |
Output:
Index of Lazyroar = 0 Index of Present = -1
Program 2: Using indexOf() with Quartet class:
// Below is a Java program to use indexOf() method  import java.util.*;import org.javatuples.Quartet;  class GfG {    public static void main(String[] args)    {        // Creating a quartet        Quartet<Integer, String, String, Double> quartet            = Quartet.with(Integer.valueOf(1),                           "Lazyroar",                           "A computer portal",                           Double.valueOf(20.18));          // Using indexOf() method for present value        int index1 = quartet.indexOf("Lazyroar");          // Printing the index1        System.out.println("Index of Lazyroar = "                           + index1);          // Using indexOf() method for absent value        int index2 = quartet.indexOf(5);          // Printing the index2        System.out.println("Index of 5 = "                           + index2);    }} |
Output:
Index of Lazyroar = 1 Index of 5 = -1
Note: Similarly, it can be used with any other JavaTuple Class.
