TRACE TABLES in Computer Science and Technology.pptx
- 1. TRACE TABLES
- 2. Introduction to Trace Tables A tool for tracking variable values during program execution Helps understand program flow and identify errors Consists of variable names as column headings and values in cells One row for each pass or iteration of the program
- 3. Components of a Trace Table Column headers: Variable names (identifiers) Rows: Each pass or iteration of the program Cells: Values of variables at each step Additional columns can include line numbers or conditions Why do you think tracking variables is important in programming?
- 4. Creating a Trace Table: Step 1 Identify all variables in the program Create column headers for each variable Add a column for line numbers if needed Example variables: count, sum, average
- 5. Creating a Trace Table: Step 2 Go through the program line by line Update variable values in each row as they change Note any conditions or decisions made How might this process help in debugging a program?
- 7. Example: Simple Counting Loop Program: Trace a program that counts from 1 to 5 and prints the count. START Declare count as integer count = 0 While count < 5: print(count) count = count + 1 ENDWHILE STOP (continues until count = 5)
- 8. Example: Simple Counting Loop Step 1 Count 1 0 2 1 3 2 4 3 5 4
- 9. Example: Calculating Average Program:Trace a program that finds the sum and average of numbers from 1 to 4 START Declare sum,count as integer sum = 0 for i =1 to 4 do sum = sum + i average = sum / 3 ENDFOR STOP
- 10. Example: Calculating Average | i | sum | average 1 0 0 2 1 .33 3 3 1 4 6 2
- 11. X Y
- 13. Common Mistakes to Avoid Forgetting to update all variables in each row Misinterpreting logical operations in truth tables Skipping steps in complex programs Not considering all possible input combinations What strategies can you use to avoid these mistakes?
- 14. Practice: Creating a Trace Table Let's practice together! Program: x = 5 y = 0 while x > 0: y = y + x x = x - 1 Create a trace table for this program What is the final value of y?