Thursday, September 4, 2025
HomeLanguagesJavaArray setBoolean() Method in Java with Examples

Array setBoolean() Method in Java with Examples

The java.lang.reflect.Array.setBoolean() method is an inbuilt method used to set a specified Boolean value to a specified index of a given object array.

Syntax:

Array.setBoolean(Object []array, int index, boolean value)

Parameter: This method takes three parameters:

  • array: array of type Object which is to be updated.
  • index: index of the array which is to be updated.
  • value: boolean value that is to be set at the given index of the given array.

Return type: This is a void type method and doesn’t returns any value. The update reflects upon the Object array passed as the argument.

Exception: This method throws following exceptions:

  • NullPointerException– when the array is null.
  • IllegalArgumentException– when the given object array is not an Array.
  • ArrayIndexOutOfBoundsException– if the given index is not in the range of the size of the array.
  • Below is the implementation of Array.setBoolean() method:

    Program 1:




    // Java code to demonstrate setBoolean()
    // method of Array class
      
    import java.lang.reflect.Array;
    public class GfG {
        // main method
        public static void main(String[] args)
        {
            // Declaring and defining boolean array
            boolean b[] = { true, false, true };
      
            // array before using setBoolean()
            System.out.print("Before Set : ");
      
            // printing the array
            for (boolean x : b) {
                System.out.print(x + " ");
            }
      
            // boolean value to be set
            boolean value = true;
      
            // setBoolean method of class Array
            Array.setBoolean(b, 1, value);
      
            // array after using setBoolean()
            System.out.print("\nAfter Set : ");
      
            // printing array
            for (boolean x : b) {
                System.out.print(x + " ");
            }
        }
    }

    
    
    Output:

    Before Set : true false true 
    After Set : true true true
    

    Program 2: To demonstrate java.lang.NullPointerException




    // Java code to demonstrate setBoolean()
    // method of Array class
      
    import java.lang.reflect.Array;
    public class GfG {
        // main method
        public static void main(String[] args)
        {
            // Declaring and defining boolean array to null
            boolean b[] = null;
      
            try {
                // boolean value to be set
                boolean c = false;
      
                // passing a null array as parameter
                Array.setBoolean(b, 5, c);
            }
            catch (Exception e) {
                System.out.println("Exception : " + e);
            }
        }
    }

    
    
    Output:

    Exception : java.lang.NullPointerException
    

    Program 3: To demonstrate java.lang.ArrayIndexOutOfBoundsException




    // Java code to demonstrate setBoolean()
    // method of Array class
      
    import java.lang.reflect.Array;
    public class GfG {
        // main method
        public static void main(String[] args)
        {
            // Declaring and defining boolean array
            boolean b[] = { true, false, true };
      
            try {
                // value to be set
                boolean c = false;
      
                // passing index as 5 when size is 3
                Array.setBoolean(b, 5, c);
            }
            catch (Exception e) {
                System.out.println("Exception : " + e);
            }
        }
    }

    
    
    Output:

    Exception : java.lang.ArrayIndexOutOfBoundsException
    

    Program 4: To demonstrate java.lang.IllegalArgumentException




    // Java code to demonstrate setBoolean()
    // method of Array class
      
    import java.lang.reflect.Array;
    public class GfG {
        // main method
        public static void main(String[] args)
        {
            // Declaring and defining boolean variable
            boolean b = true;
      
            try {
                // value to be set
                boolean c = false;
      
                // passing variable in the place of an array
                Array.setBoolean(b, 5, c);
            }
            catch (Exception e) {
                System.out.println("Exception : " + e);
            }
        }
    }

    
    
    Output:

    Exception : java.lang.IllegalArgumentException: Argument is not an array
    
RELATED ARTICLES

Most Popular

Dominic
32262 POSTS0 COMMENTS
Milvus
81 POSTS0 COMMENTS
Nango Kala
6626 POSTS0 COMMENTS
Nicole Veronica
11799 POSTS0 COMMENTS
Nokonwaba Nkukhwana
11857 POSTS0 COMMENTS
Shaida Kate Naidoo
6749 POSTS0 COMMENTS
Ted Musemwa
7025 POSTS0 COMMENTS
Thapelo Manthata
6696 POSTS0 COMMENTS
Umr Jansen
6716 POSTS0 COMMENTS