Computer Programming 2 Lecture 1: Advanced Array Data Structure Using Methods Prepared & Presented by: Mahmoud Rafeek Alfarra MINISTRY OF EDUCATION & HIGHER EDUCATION COLLEGE OF SCIENCE AND TECHNOLOGY (CST) KHANYOUNIS- PALESTINE

و من يتقِ الله... قال ربي سبحـانه : و لو أن أهل القرى أمنوا و اتقوا لفتحنا عليهم بركات من السماء و الأرض. Mahmoud Rafeek Alfarra 2 Downloaded from شريحـة ثابتـة لعلنا نحسن من خلالها أخلاقنـا و أفعالنا لنفوز يوم الامتحان الحقيقي

Out Lines Mahmoud Rafeek Alfarra Downloaded from Downloaded from 3 Revision about Array data structure Example: Store the even elements in array What is Multidimensional Arrays? Applications !! Example: X O’s Project.

Revision about Array data structure Mahmoud Rafeek Alfarra Downloaded from Downloaded from 4 An array is a special type of object that can hold an ordered collection of elements. The type of the elements of the array is called the base type of the array; the number of elements it holds is a fixed attribute called its length. Java supports arrays of all primitive and reference types.

Revision about Array data structure Mahmoud Rafeek Alfarra Downloaded from Downloaded from 5 Arrays are static data structure (which means ?!!).

Revision about Array data structure Mahmoud Rafeek Alfarra Downloaded from Downloaded from 6 To Create & initialize the one dim. array: basetype [] arrayname = new basetype [length]; Arrayname[0] = val1; Arrayname[1] = val2; Arrayname[…] = val n ; Or basetype [] arrayname = { val1, val2, val3, … };

Revision about Array data structure Mahmoud Rafeek Alfarra Downloaded from Downloaded from 7 Examples: int [] salary = new int [3]; salary[0] = 487; salary[1] = 600; salary[2] = 894; Or int [] salary = { 487, 600, 894 };

Example : Store even elements in array Mahmoud Rafeek Alfarra Downloaded from Downloaded from 8 Using Procedural programming, Write a program to store the even numbers from int To int in array. Then, print the summation of the array’s elements.

Mahmoud Rafeek Alfarra Downloaded from Downloaded from 9 import javax.swing.JOptionPane; public class SumEvenArray { public static void even (int low, int high){ int size = (high - low)/2 +2; int [] evenarr = new int [size]; int len=0; for (int i = low; i<=high; i++) { if (i%2==0){ evenarr[len] = i; len++;} } sumarr(evenarr); } public static void sumarr(int [] evenarr) { int sum=0; for (int i =0; i<evenarr.length; i++) sum= sum+evenarr[i]; JOptionPane.showMessageDialog(null, "Sum is: "+sum); } public static void main(String[] args) { even(100, 110); } }

What is Multidimensional Arrays? Mahmoud Rafeek Alfarra Downloaded from Downloaded from 10 Multidimensional arrays with two dimensions are often used to represent tables of values consisting of information arranged in rows and columns. To identify a particular table element, we must specify two indices. By convention, the first identifies the element's row and the second its column.

What is Multidimensional Arrays? Mahmoud Rafeek Alfarra Downloaded from Downloaded from 11 To Create & initialize the two dim. array: basetype [] [] arrayname = new basetype [r][c]; Arrayname[0] [0]= val1; Arrayname[0] [1] = val2; Arrayname[…][…] = val n ; Or basetype [] [] arrayname = { {val1, val2}, {val3, …} };

What is Multidimensional Arrays? Mahmoud Rafeek Alfarra Downloaded from Downloaded from 12 To Create & initialize the two dim. array: int [] [] table = new int [3][2]; table[0] [0]= 3; table[0] [1] = 5; table[0] [2] = 4; table[…][…] = val n ; Or int [] [] table = { {3, 5, 4}, {valn, …} };

What is Multidimensional Arrays? Mahmoud Rafeek Alfarra Downloaded from Downloaded from 13 Java does not support multidimensional arrays directly, but it does allow the programmer to specify one-dimensional arrays whose elements are also one-dimensional arrays.

Example : Mahmoud Rafeek Alfarra Downloaded from Downloaded from 14 Using Procedural programming, Write a program to store the following figure (multiple of 1, 2, 3, 4 by its successors to three times)

Lets thinking now … Mahmoud Rafeek Alfarra Downloaded from Downloaded from ? How To

Next Lecture … Mahmoud Rafeek Alfarra Downloaded from Downloaded from 16 Continue Array’s Application