class17 Notes - 1 1 IST 240 Tue (3/18) Chapter 7: Arrays...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 1 IST 240 Tue (3/18) Chapter 7: Arrays Hwk #7: Ex 7.1, 7.3, 7.5, PP 7.1 Due: Sun 3/23 11:59pm Review JCreator workspace/project/file setup GridButtonExample.java: 2-D JButton example Thu (3/20) Chapter 8: Inheritance Tue (3/25) Teamwork: Implementation Thu (3/27) Review Ch 5-8 Chapter 9: Polymorphism & Interfaces Tue (4/1) Exam #2: Ch 5-8 2 7.1 Arrays An array is an ordered list of values 0 1 2 3 4 5 6 7 8 9 79 87 94 82 67 98 87 81 74 91 An array of size N is indexed from zero to N-1 scores The entire array has a single name Each value has a numeric index This array holds 10 values that are indexed from 0 to 9 2 3 7.1 Arrays A particular value in an array is referenced using the array name followed by the index in brackets For example, the expression scores[2] refers to the value 94 (the 3rd value in the array) That expression represents a place to store a single integer and can be used wherever an integer variable can be used 4 7.1 Arrays 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]); 3 5 7.1 Arrays 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 6 7.1 Arrays Another way to depict the scores array scores 79 87 94 82 67 98 87 81 74 91 4 7 7.2 Declaring Arrays The scores array could be declared as follows int scores = new int[10]; ( equally valid: int scores = new int[10]; ) The type of the variable scores is int (an array of integers) The reference variable scores is set to a new array object that can hold 10 integers Some other examples of array declarations float prices = new float[500]; boolean flags; flags = new boolean[20]; char codes = new char[1750]; 8 7.2 Using Arrays The iterator version of the for loop can be used when...
View Full Document

This note was uploaded on 03/31/2008 for the course IST 240 taught by Professor Tracymullen during the Spring '08 term at Pennsylvania State University, University Park.

Page1 / 12

class17 Notes - 1 1 IST 240 Tue (3/18) Chapter 7: Arrays...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online