QBASIC program to display the input string in reverse order.

 

If you are a computer science student or a programming enthusiast, you might have come across the QBASIC programming language. QBASIC is an old-school programming language that was popular in the 1990s. Despite being outdated, QBASIC still has its uses, and it can be used to create simple programs like the one we are going to discuss in this article.

Introduction to QBASIC

QBASIC is a high-level programming language that was developed by Microsoft Corporation. QBASIC stands for Quick Beginner's All-purpose Symbolic Instruction Code. QBASIC is an interpreted language, which means that the code is executed line-by-line by the computer's CPU.

QBASIC is easy to learn, and it is often used as a starting point for people who are new to programming. QBASIC is also useful for creating simple programs quickly.

The Problem Statement

In this article, we are going to create a QBASIC program that displays the input string in reverse order. The program should take an input string from the user and display the reverse of the string.

For example, if the user enters the string "Hello World," the program should display "dlroW olleH."

Understanding the Solution

To solve this problem, we need to take an input string from the user and then display the reverse of the string. We can achieve this by using a loop that iterates through each character of the string and appends it to a new string in reverse order.

Here is the algorithm we are going to use:

1. Take an input string from the user.
2. Initialize an empty string to store the reverse of the input string.
3. Iterate through each character of the input string in reverse order.
4. Append each character to the empty string.
5. Display the reverse of the input string.

The QBASIC Program

Now that we have an algorithm, we can write the QBASIC program to display the input string in reverse order. Here is the code:

Explanation:

Let's go through the code line by line to understand what it does.

• The first line of the code clears the screen using the CLS command.
• The second line of the code takes an input string from the user using the INPUT command. The string is stored in the variable "str."
• The third line of the code initializes an empty string called "reverse" to store the reverse of the input string.
• The fourth line of the code starts a loop that iterates through each character of the input string in reverse order. The loop uses the LEN function to get the length of the input string and then iterates from the last character to the first character using the STEP -1 command.
• The fifth line of the code uses the MID$ function to extract each character of the input string and append it to the "reverse" string.
• The sixth line of the code ends the loop.
• The seventh line of the code displays the reverse of the input string using the PRINT command.
• The last line of the code ends the program using the END command.

We can solve this program by using SUB and FUNCTION procedures also.

 

FAQs

Q: What is QBASIC? 

A: QBASIC is a high-level programming language used to create and execute computer programs.

Q: Can I write a QBASIC program on any computer? 

A: QBASIC can be run on any computer that has a QBASIC interpreter installed.

Q: Why is it useful to write a QBASIC program to display an input string in reverse order? 

A: This program is useful when you want to reverse a string, such as a name or a sentence.

Conclusion

In conclusion, writing a QBASIC program to display an input string in reverse order is easy and fun. With our step-by-step instructions, helpful tips, and FAQs, you can write your own program in no time. QBASIC is an easy-to-learn language that is suitable for beginners who want to learn programming. We hope this article has been helpful and informative. Happy programming!