Software Development Life Cycle
- 1. Chapter 1 Program Development Cycle
- 2. Designing a Program Design requires planning…that follows the above steps Called Program Development Cycle Cycle is repeated until NO errors appear in the program. Design the program Write the methods Test the methods Debug the methods
- 3. Designing the Program Determine what the app is supposed to do. Read a problem statement that describes the which objects will appear in the app, and the actions that are to take place. What is the “Story”? Design the program Write the methods Test the methods Debug the methods
- 4. Designing the Program Break the problem statement down into series of steps Pseudocode Algorithm or Flowchart Design the program Write the methods Test the methods Debug the methods
- 5. Writing the methods Design steps (pseudocode or flowchart) provides model for writing the methods Drag tiles into Editor to assemble instructions Instructions should follow the order of the Design steps Pseudocode and flowchart may NOT be at the detail of the final instructions This step becomes more involved when you begin to write your own methods. Design the program Write the methods Test the methods Debug the methods
- 6. Testing Test to make sure it meets the following criteria: Does it do what it was intended to do? Does it have any errors? Any undesired results? Is it efficient? Are there unnecessary steps? If the criteria are NOT met, then debugging occurs Always create the program in small parts to make testing easier Design the program Write the methods Test the methods Debug the methods TEST! TEST! TEST!
- 7. Designing a Program Debugging means to determine what must be corrected or modified to get the program to work correctly Logical errors (bug) is a mistake that produces an incorrect result, but the program still runs. Instructions in an incorrect order may produce incorrect results Passing incorrect values as arguments can cause logical errors What is the logical error? Syntax errors are instructions written incorrectly in a language Alice has no syntax Design the program Write the methods Test the methods Debug the methods
- 8. Checkpoint 1. What are the steps in the program development cycle? 2. What are two tools that you can use to break down a problem into a series of steps? 3. What is a logical error? 4. When testing a method, what are three criteria that you should make sure the method meets? 2-8 2.3