CSE110 Lecture 03

Principles of Programming with Java
Classes, methods, and variables
(202205)

Transcript

1. CSE110 Principles of Programming with Java Lecture 03: Classes, methods, and variables Javier Gonzalez-Sanchez javiergs@asu.edu javiergs.engineering.asu.edu | javiergs.com Office Hours: By appointment
2. IDE Using IntelliJ
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10. IDE Using Eclipse
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21. IDE Using TutorialsPoint.com
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23. Java Classes, Methods and Variables
24. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 24 Java Program Structure • A program is made up of one or more classes • A class contains one or more methods • A method contains program statements
25. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 25 Java Program Structure • program statements can be: • Variables – places to store information • Instructions – actions to be done
26. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 26 Previously… and static public class TheClassName { } public static void theFirstMethodName() { } public static void secondMethodName(){ } // instructions go here // instructions go here // variables go here // variables go here // variables go here public static void main( ) { } // instructions go here // variables go here
27. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 27 Example without main()
28. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 28 main() method • All programs should have one and only one main() method. • Trying to execute a class without a main() method generates a compilation error
29. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 29 Example with main()
30. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 30 Example main() calling methods
31. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 31 Template public class TheClassName { } public static void theFirstMethodName() { } public static void secondMethodName(){ } // instructions go here // instructions go here // variables go here // variables go here // variables go here public static void main( ) { } // instructions go here // variables go here
32. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 32 Global Variable
33. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 33 Error
34. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 34 Homework Read Sections 2.1, 2.2, and 2.3
35. CSE110 - Principles of Programming Javier Gonzalez-Sanchez javiergs@asu.edu Summer 2022 Disclaimer. These slides can only be used as study material for the class CSE110 at ASU. They cannot be distributed or used for another purpose.