10 Java Interview Sample Coding Questions On Arrays

10 Java Interview Sample Coding Questions On Arrays

10 Java Interview Sample Coding Questions On Arrays

1) What happens when you compile and run this program?
public class ArraysInJava {
      public static void main(String[] args) {
            int[] i = new int[0];

            System.out.println(i[0]);
      }
}
Ans : You will get ArrayIndexOutOfBoundsException at run time.
2)  What will be the output of this program?
public class ArraysInJava {
      public static void main(String[] args) {
            int[] a = new int[3];

            a[1] = 50;

            Object o = a;

            int[] b = (int[]) o;

            b[1] = 100;

            System.out.println(a[1]);

            ((int[]) o)[1] = 500;

            System.out.println(a[1]);
      }
}

Ans :
100
500
3) What will be the outcome of the following program?
public class ArraysInJava {
      static final int[] a;

      static {
            a = new int[] { 1, 2, 3 };
      }

      public static void main(String[] args) {
            a = new int[5];
      }
}

Ans : Compile time error.
4)What will be the outcome of this program?
public class ArraysInJava {
      public static void main(String[] args) {
            int[] a = { 1, 2, 3, 4, 5, 8 };

            System.out.println(a[-1]);
      }
}

Ans : ArrayIndexOutOfBoundsException at run time.
5) What happens when you compile and run the following program?
public class ArraysInJava {
      public static void main(String[] args) {
            int[][] a = { { 1, 2, }, { 3, 4 } };

            int[] b = (int[]) a[1];

            Object o1 = a;

            int[][] a2 = (int[][]) o1;

            int[] b2 = (int[]) o1;

            System.out.println(b[1]);
      }
}

Ans : Line 13 throws ClassCastException at run time.
6) What will be the output of this program?
public class ArraysInJava {
      static void methodOne(int[] a) {
            int[] b = new int[5];

            a = b;

            System.out.print(a.length);

            System.out.print(b.length);
      }

      public static void main(String[] args) {
            int[] a = new int[10];

            methodOne(a);

            System.out.print(a.length);
      }
}

Ans : 5510
7) Will this program compiles and runs successfully?
public class ArraysInJava {
      public static void main(String[] args) {
            int[] a = { 1 };

            int[] b[] = { { 1 } };

            int[][] c[] = { { { 1 } } };

            int[][] d[][] = { { { { 1 } } } };
      }
}

Ans : Yes.
8) What will be the output of this program?
public class ArraysInJava {
      public static void main(String[] args) {
            String[][][][] colors = { { { { "RED", "GREEN", "BLUE" },

                        { "GREEN", "RED", "BLUE" } },
                        { { "ORANGE", "GREEN", "WHITE" },

                                    { "BLACK", "INDIGO", "BLUE" } } },
                        { { { "SKY BLUE", "ALMOND", "AQUA" },

                                    { "APPLE GREEN", "PINK", "BLUE GREEN" } },
                                    { { "VIOLET", "BRASS", "GREY" },

                                                { "BROWN", "INDIGO", "CHERRY" } } } };

            System.out.println(colors[1][0][1][0]);

            System.out.println(colors[0][1][0][1]);

            System.out.println(colors[0][0][0][2]);

            System.out.println(colors[1][1][1][2]);

            System.out.println(colors[0][0][0][0]);

            System.out.println(colors[1][1][1][1]);
      }
}

Ans :
APPLE GREEN
GREEN
BLUE
CHERRY
RED
INDIGO
9) Does below program compile successfully?
class A {
      int i = 10;
}

class B extends A {
      int j = 20;
}

class C extends B {
      int k = 30;
}

class D extends C {
      int m = 40;
}

public class ArraysInJava {
      public static void main(String[] args) {
            A[] a = { new A(), new B(), new C(), new D() };

            System.out.println(a[3].i);

            System.out.println(a[2].j);

            System.out.println(a[1].k);

            System.out.println(a[0].m);
      }
}

Ans : No, It gives compile time error
10) What will be the output of this program?
public class ArraysInJava {
      static Double[] methodOne(Double[] D) {
            D[1] = 36.25;

            return methodTwo(D);
      }

      static Double[] methodTwo(Double[] D) {
            D[1] = 62.36;

            return methodThree(D);
      }

      static Double[] methodThree(Double[] D) {
            D[1] = 93.58;

            return D;
      }

      public static void main(String[] args) {
            Double[] D = { 10.55, 25.36, 58.29, 74.32, 32.21 };

            D = methodOne(D);

            System.out.println(D[1]);
      }
}

Ans : 93.58



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