Overview: Hands-On Lab Allows You To Follow And Experiment

Overviewthis Hands On Lab Allows You To Follow And Experiment With Th

This hands-on lab allows you to follow and experiment with the critical steps of developing a program including the program description, analysis, design (program design, pseudocode), test plan, and implementation with C code. The example provided uses sequential, selection, and repetition statements. The program will calculate the sum of 3 integers input by the user and display a message if the sum is greater than 100. Additional modifications involve testing conditions for negative sums, multiple range-based conditions, and handling invalid inputs. You will also create new C code implementations based on these requirements, including comprehensive testing with various input cases.

Paper For Above instruction

The development of a simple program to compute the sum of three integers and make decisions based on the result exemplifies fundamental programming concepts such as user input handling, control structures, and logical decision-making. This process spans the stages of analysis, design, coding, and testing, providing a structured approach to software development. This paper provides an in-depth exploration of each step involved in creating such a program, emphasizing modification and testing aspects critical for robust software development.

Program Description and Analysis

The core purpose of the program is to request three integer inputs from the user and compute their sum. Based on the total, the program will display messages; specifically, it will notify if the sum exceeds 100. Analysis indicates the use of sequential instructions for input collection and calculation, combined with selection statements for decision-making. Variables such as value1, value2, value3, and sum are used to store user inputs and their total. These variables are integer types, ensuring precise numerical calculations.

The program's logic involves prompting the user for each number, reading the inputs successfully, calculating the sum, and then using conditional statements to determine which message to produce. The initial code demonstrates straightforward use of conditional statements and input/output functions in C, serving as a foundational example for further modifications.

Design and Pseudocode

The program's design includes a main function that declares variables, prompts for inputs, calculates the sum, and uses conditions to display messages. The pseudocode outline is as follows:

Main:


Declare value1, value2, value3, sum as Integer


Initialize sum to zero


Prompt user for value1


Read value1


Prompt user for value2


Read value2


Prompt user for value3


Read value3


Calculate sum = value1 + value2 + value3


Print "Sum is" + sum


If sum > 100 then


Print "Sum is over 100"


End if


End

This structure provides clarity and sets a foundation for multiple modifications.

Test Plan

To verify the program functions correctly, various test cases are designed, including:

  • Test Case 1: Inputs: 15, 25, 30; Expected Output: Sum = 70; no message about exceeding 100.
  • Test Case 2: Inputs: 100, 200, 300; Expected Output: Sum = 600; message "Sum is over 100".
  • Test Case 3: Inputs: -100, -100, -200; Expected Output: Sum = -400; no over-100 message, but additional conditions will be tested later.

These test cases cover typical, boundary, and negative inputs, ensuring robustness.

Code Implementation and Modifications

The basic C code snippet is provided to demonstrate the calculation and decision-making process:

include <stdio.h>


int main() {


int value1, value2, value3, sum;


sum = 0;


printf("Enter an Integer for value1\n");


scanf("%d", &value1);


printf("Enter an Integer for value2\n");


scanf("%d", &value2);


printf("Enter an Integer for value3\n");


scanf("%d", &value3);


sum = value1 + value2 + value3;


printf("Sum is %d\n", sum);


if (sum > 100)


printf("Sum is over 100\n");


return 0;


}

Modifications to this code include adding additional conditional statements to evaluate negative sums, as well as implementing range-based decision structures using if-else if-else constructs.

Enhancement 1: Negative Sum Check

Adding an extra condition to check if the sum is negative involves inserting an if statement after the sum calculation:

if (sum 

printf("Sum is negative\n");

This provides immediate feedback on negative totals, supporting comprehensive input testing.

Enhancement 2: Multiple Range Conditions

To categorize the sum into four distinct ranges, use a structured if-else if-else statement:

if (sum 

printf("Sum is negative\n");


} else if (sum >= 0 && sum 

printf("Sum is between 0 and 100\n");


printf("Sum is within the acceptable range\n");


} else if (sum > 100 && sum 

printf("Sum is greater than 100 and up to 500\n");


} else {


printf("Sum exceeds 500\n");


}

Note that braces are used to include multiple statements within a single condition.

Testing and Validation

Developing a new test table corresponding to these modifications involves selecting input values for each case:

InputExpected Output
50, 25, 10Sum is 85; Sum is between 0 and 100; Sum is within the acceptable range
-50, -25, -10Sum is -85; Sum is negative
200, 350, 100Sum is 650; Sum exceeds 500

Implementing Custom Program with Error Handling

Further, a robust implementation involves handling invalid inputs such as non-integer entries. Incorporating input validation ensures program stability. This can be achieved by checking the return value of scanf() and prompting the user again if invalid input is detected. Example with input validation:

include <stdio.h>


int main() {


int value1, value2, value3, sum;


int result;


result = 1;


printf("Enter an Integer for value1\n");


while ((result = scanf("%d", &value1)) != 1) {


printf("Invalid input. Please enter a valid integer for value1:\n");


while (getchar() != '\n'); // clear buffer


}


printf("Enter an Integer for value2\n");


while ((result = scanf("%d", &value2)) != 1) {


printf("Invalid input. Please enter a valid integer for value2:\n");


while (getchar() != '\n');


}


printf("Enter an Integer for value3\n");


while ((result = scanf("%d", &value3)) != 1) {


printf("Invalid input. Please enter a valid integer for value3:\n");


while (getchar() != '\n');


}


sum = value1 + value2 + value3;


printf("Sum is %d\n", sum);


if (sum > 100)


printf("Sum is over 100\n");


if (sum 

printf("Sum is negative\n");


// range-based decisions can follow


return 0;


}

This ensures the program is both user-friendly and error-resistant.

Conclusion

Constructing a program to sum integers and evaluate the total's range involves understanding control structures, user input, and decision-making. The process starts with analysis, proceeds through systematic design and pseudocode, and culminates in implementation and rigorous testing. Including additional conditions and error handling enhances robustness and usability. These practices demonstrate core principles of reliable software development and prepare programmers for more complex tasks.

References

  • Belotti, F., et al. (2019). Programming in C. Pearson Education.
  • Kernighan, B. W., & Ritchie, D. M. (1988). The C Programming Language. Prentice Hall.
  • Sharma, S. (2018). Learning C Programming. McGraw-Hill Education.
  • Bannier, M. (2020). Hands-On Introduction to Programming. O'Reilly Media.
  • The GNU Operating System. (2021). C Programming Guide. https://gcc.gnu.org/onlinedocs/gcc/C-Programming.html
  • Hariri, S., & Radenski, A. (2009). Introduction to Programming in C. Springer.
  • Deitel, H. M., & Deitel, P. J. (2017). C How to Program. Pearson.
  • Jones, R. (2012). Effective C Programming. Safari Books Online.
  • Online C Compiler Documentation. (2022). https://www.onlinegdb.com/online_c_compiler
  • Lea, D. (2020). Error Handling in C. Linux Journal, 2020(278), 58-63.

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