Topics Discussed: Arrays, subscripts, iterating through arrays

Source Code Below

15.2

Topics discussed: Same as above

Source Code for Lesson 15-1 / 15-2

```import java.util.Scanner;
class Jtutorial1 {
public static void main(String args[]){
Scanner input = new Scanner(System.in);

//int i= 5;    i(5);
//int anArray[] = new int[5];

//anArray[ | | | | ];
//anArray[0|0|0|0|0]; // initialize to 0
//anArray[0|1|2|3|4]; // index. 0th, 1st, 2nd, 3rd, 4th
//anArray[1|2|3|4|5]; //
//anArray[ | |3| | ]; // 3

System.out.println("\nHow many items would you like to enter? : ");
int x = input.nextInt(); //3

int itemArray[] = new int[x];
double itemCost[] = new double[x];

for (int i = 0; i < itemArray.length; i++){ // initializing arrays to 0
itemArray[i] = 0; // [i] Subscript.
itemCost[i] = 0;  // anArray[2] i=2  anArray[i]
//itemArray / itemCost[ 0 | 0 | 0 ]  // 0, 1, 2
}

for(int i=0; i< itemArray.length; i++){
System.out.println("\nEnter the unique, item ID: ");
itemArray[i] = input.nextInt();

System.out.println("\nEnter the cost for that item: ");
itemCost[i] = input.nextDouble();
}
System.out.println();
System.out.println();
System.out.println("Price list: ");
for(int i=0; i < itemArray.length; i++){
System.out.println("The value of i is: " + i + "  Item Number: " + (itemArray[i]) + " = \$" + itemCost[i]);
}

}//end main
}//end class

//Create an array, to enter user entered numbers.

//10

//a, a, a, a, c, c, c, d, f, g```

Homework:

```ork download
copy

Create an array of characters that correspond to SOMETHING meaningful to you and output that many characters.

Example, my name

'Damien'

User enters 3

program outputs 'Dam'```

Arrays
Arrays are the most basic multi-variable container made available in java. The syntax is pretty simple, but the implementation can be confusing if you don’t have a programming background. The basic specifications of an array is that it’s a basic, 0-indexed, template’d, data structure that can be created with either explicit values or in an empty state.

```int anArray[] = new int[7]; // Creates an array that can hold 7 ints.
for(int i=0; i< anArray.length(); i++){
anArray[i] = i; // sets the array equal to it's index based off the iteration in a loop.
}```

Arrays can be iterated through easily with loops, especially by for loops.

The Subscript
The subscript is the way that we access a certain part of an array. `anArray[0]` would refer to the ‘first’ (remember, 0-indexed) location in the array. Therefore the subscript in this case would be 0. Changing the subscript from within a loop is fairly common practice in Object oriented programming.