• An array is an ordered list of values
• An array of size N is indexed from zero to N-1
• A particular value in an array is referenced using the array name followed by the index in brackets
• For example, the expression

  scores[2]

• That expression represents a place to store a single integer and can be used wherever an integer variable can be used
• For example, an array element can be assigned a value, printed, or used in a calculation:

    scores[2] = 89;
  
    scores[first] = scores[first] + 2;
  
    mean = (scores[0] + scores[1])/2;
  
    System.out.println ("Top = " + scores[5]);

• The values held in an array are called array elements
• An array stores multiple values of the same type – the element type
• The element type can be a primitive type or an object reference
• Therefore, we can create an array of integers, an array of characters, an array of String objects, an array of Coin objects, etc.
• In Java, the array itself is an object that must be instantiated
• Definitions using new

  double [] scores = new double [NUMBER_OF_STUDENTS];

  • The above statement will:
  • allocate block of memory to hold 7 doubles
  • initialize block with zeros
  • returns the address of the block
  • create a handle called scores
  • store address of the block in scores

/*************************************************************************
* Arrays in Java Example
*
*************************************************************************/
package lesson1;
public class MyClass {
public static void main(String[] args) {
int[] myintarray = {100,31,26,48,52};
/*
int[] myIntArray = new int[3];
int[] myIntArray = {1,2,3};
int[] myIntArray = new int[]{1,2,3};
*/
int index=0;
while(index < 5) {
System.out.println(myintarray[index]);
index++;
}
}
}