package javaapplication1;

public class JavaApplication1 {

    public static void main(String[] args) {
        int i,a,b;
        int aa[] = new int [20];
        a=1;
        b=10;
            for (i = 0; i <= 20; i++) {
                aa[i]=cub (a,b);
                System.out.format("Hello world name = %d, ",aa[i]);
            }
        cub (a,b);
        System.out.format("Hello world name = %d \n",b-a+1);
    }

    public static int cub(int a,int b) {
        int c, i;
        c=(int)(a + Math.random() * (b-a+1));
        return (c);
    }
}

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 20
	at javaapplication1.JavaApplication1.main(JavaApplication1.java:18)
Hello world name = 9, Hello world name = 5, Hello world name = 4, Hello world name = 6, Hello world name = 8, Hello world name = 4, Hello world name = 4, Hello world name = 10, Hello world name = 10, Hello world name = 3, Hello world name = 9, Hello world name = 10, Hello world name = 5, Hello world name = 7, Hello world name = 1, Hello world name = 1, Hello world name = 4, Hello world name = 5, Hello world name = 1, Hello world name = 6, ...\run.xml:53: Java returned: 1

            for (i = 0; i <= 20; i++) {
                aa[i]=cub (a,b);
                System.out.format("Hello world name = %d, ",aa[i]);
            }

int aa[] = new int [20];

            for (i = 0; i<= 20; i++) 

            for (i = 0; i<= 20; i++) 

- int aa[] = new int [ 21 ];
- for (i = 0; i  <  20; i++)

package javaapplication8;

public class JavaApplication8 {

    public static void main(String[] args) {
        Circle o1 = new Circle();
        float c,r;

        r=5;
        c=o1.lenc(r);
        
        System.out.format(" %5.2f \n",c);
    }

    class Circle {
        float x,y,r;
        public float lenc (float r){
            float c;
            c=(float) (3.14*r*2);
            return (c);
        }
    }
}

        Circle o1 = new Circle();

package javaapplication8;

public class JavaApplication8 {

    public static void main(String[] args) {
        Circle o1 = new Circle();
        float c,r;

        r=5;
        c=o1.lenc(r);
        
        System.out.format(" %5.2f \n",c);
    }

    class Circle {
        float x,y,r;
        public float lenc (float r){
            float c;
            c=(float) (3.14*r*2);
            return (c);
        }
    }
}

        Circle o1 = new Circle();

package javaapplication8;

public class JavaApplication8 {

    public static void main(String[] args) {
        Circle o1 = new Circle();
        float c,r;

        r=5;
        c=o1.lenc(r);
        
        System.out.format(" %5.2f \n",c);
    }

    class Circle {
        float x,y,r;
        public float lenc (float r){
            float c;
            c=(float) (3.14*r*2);
            return (c);
        }
    }
}

        Circle o1 = new Circle();

public static class Circle { }

public static class Circle { }

public static void main(String[] args) {
    JavaApplication8 javaApp8 = new JavaApplication8();
    JavaApplication8.Circle o1 = javaApp8.new Circle();
    float c, r;

    r = 5;
    c = o1.lenc(r);

    System.out.format(" %5.2f \n", c);
}

import java.util.Scanner;
import static java.lang.Math.*;