Computer Programming 2

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

2. و من يتقِ الله ... قال ربي سبحـانه: و لو أن أهل القرى أمنوا و اتقوا لفتحنا عليهم بركات من السماء و الأرض. شريحـة ثابتـة لعلنا نحسن من خلالها أخلاقنـا و أفعالنا لنفوز يوم الامتحان الحقيقي Downloaded from http://staff.cst.ps/mfarra

3. Out Lines Revision about Array data structure Example: Store the even elements in array What is Multidimensional Arrays? Applications !! Example: X O’s Project. Downloaded from http://staff.cst.ps/mfarra

4. Revision about Array data structure 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. Downloaded from http://staff.cst.ps/mfarra

5. Revision about Array data structure Arrays are static data structure (which means ?!!). Downloaded from http://staff.cst.ps/mfarra

6. Revision about Array data structure To Create & initialize the one dim. array: basetype [] arrayname = new basetype[length]; Arrayname[0] = val1; Arrayname[1] = val2; Arrayname[…] = valn; Or basetype [] arrayname = { val1, val2, val3, … }; Downloaded from http://staff.cst.ps/mfarra

7. Revision about Array data structure Examples: int [] salary = new int [3]; salary[0] = 487; salary[1] = 600; salary[2] = 894; Or int [] salary = { 487, 600, 894 }; Downloaded from http://staff.cst.ps/mfarra

8. Example : Store even elements in array 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. Downloaded from http://staff.cst.ps/mfarra

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); } } Downloaded from http://staff.cst.ps/mfarra

10. What is Multidimensional Arrays? 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. Downloaded from http://staff.cst.ps/mfarra

11. What is Multidimensional Arrays? To Create & initialize the two dim. array: basetype[] [] arrayname = new basetype[r][c]; Arrayname[0] [0]= val1; Arrayname[0] [1] = val2; Arrayname[…][…] = valn; Or basetype[] [] arrayname = { {val1, val2}, {val3, …} }; Downloaded from http://staff.cst.ps/mfarra

12. What is Multidimensional Arrays? 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[…][…] = valn; Or int [] [] table= { {3, 5, 4}, {valn, …} }; Downloaded from http://staff.cst.ps/mfarra

13. What is Multidimensional Arrays? 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. Downloaded from http://staff.cst.ps/mfarra

14. Example : Using Procedural programming, Write a program to store the following figure (multiple of 1, 2, 3, 4 by its successors to three times). Downloaded from http://staff.cst.ps/mfarra

15. Lets thinking now … ? How To Downloaded from http://staff.cst.ps/mfarra

16. Next Lecture … Continue Array’s Application Downloaded from http://staff.cst.ps/mfarra