The document provides an introduction to arrays in Java, explaining their dynamic creation, components, indexing, and memory allocation. It includes multiple code examples illustrating array declaration, initialization, and access techniques. Additionally, it references online documentation for further exploration of Java arrays.

1. Arrays

2. Introduction
● Arrays are dynamically created objects
● Components - These variables are called the components. All are in same
type
● An array object contains a number of variables.(empty - Array has no
elements/components)
● index (location of the component)
● length of the array

3. Example 1
public class Arrayxsample {
public static void main(String[] args) {
int a[] = {1};
System.out.println(a[0]);
}
}

4. Example 2
public class Arrayxsample {
public static void main(String[] args) {
int a[] = {1,2,3,4,5};
System.out.println(a[3]);
}
}

5. Example 3
public class Arrayxsample {
public static void main(String[] args) {
int [] a = {4,3};
System.out.println(a[1]);
}
}

6. Example 4
public class Arrayxsample {
public static void main(String[] args) {
int [] a = {"4","3"};
System.out.println(a[1]);
}
}

7. Example 5
public class Arrayxsample {
public static void main(String[] args) {
int [] a = {1,2};
System.out.println(a[5]);
}
}

8. Declaring and allocation
int intArray[]; //declaring array
intArray = new int[20]; // allocating memory to array

9. Example 6
public class Arrayxsample {
public static void main(String[] args) {
int a[] = new int[5];
System.out.println(a[3]);
}
}

10. Example 7
public class Arrayxsample {
public static void main(String[] args) {
int [] a = new int [5];
a[0]=5;
a [4]=1;
System.out.println(a[4]);
}
}

11. Example 8
public class Arrayxsample {
public static void main(String[] args) {
int [2] a = new int [];
System.out.println(a[1]);
}
}

12. Example 9
public class Arrayxsample {
public static void main(String[] args) {
int [2] a = int a [];
System.out.println(a[1]);
}
}

13. Example 10
public class Arrayxsample {
public static void main(String[] args) {
int [] a = new int [4];
System.out.println(a[5]);
}
}

14. Example 11
public class Arrayxsample {
public static void main(String[] args) {
int [] a = new int [20];
for(int i =0;i<20;i++) {
a[i]=i;
}
System.out.println(a[15]);
}
}

15. Example 12
public class Arrayxsample {
public static void main(String[] args) {
int[] intArray = new int[]{ 1,2,3,4,5,6,7,8,9,10 };
System.out.println(intArray[5]);
}
}

16. expand this
public class Arrayxsample {
public static void main(String[] args) {
byte[] apple, orange, cake[];
int x,y[],z[];
}
}

17. Example 13
public class Arrayxsample {
public static void main(String[] args) {
int[] intArray = new int[]{ 1,2,3,4,5,6,7,8,9,10 };
System.out.println(intArray.length);
}
}

18. Example 14
public class Arrayxsample {
public static void main(String[] args) {
int[][] intArray = {{1,2},{3,4,5}};
System.out.println(intArray[0][1]);
System.out.println(intArray[1][0]);
System.out.println(intArray[1][2]);
}
}

19. Example 15
public class Arrayxsample {
public static void main(String[] args) {
int[][][] intArray = {{{1,2},{3,4}},{{5},{6,7,8}},{{9},{10,11,12}}};
System.out.println(intArray[0][1][0]);
System.out.println(intArray[1][0][0]);
System.out.println(intArray[2][1][2]);
}
}

20. Example 16
public class Arrayxsample {
public static void main(String[] args) {
int i,j,k;
int[][][] intArray = new int[100][100][100] ;
for(i=0,j=0,k=0;(i>10 || j> 0 && k>0);i++,j=j+2,k++) {
intArray[i][j][k]= (i+j)*k;
}
System.out.println(intArray[0][0][0]);
}
}

23. References
• https://docs.oracle.com/javase/specs/jls/se8/html/jls-10.html
• https://docs.oracle.com/javase/10/docs/api/java/util/Arrays.html

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