Control Structures in C: An In-Depth Guide

 

Control Structures in C

Control structures are an essential part of any programming language, and C is no exception. Control structures allow you to control the flow of execution of a program, making it possible to perform complex operations with ease.

In this tutorial, we will explore the different control structures in C, including the if...else statement, the switch statement, and the various loops (for, while, and do...while).

Table of Contents

  1. The if...else Statement
  2. The switch Statement
  3. The for Loop
  4. The while Loop
  5. The do...while Loop
  6. Loop Control Statements
    • break
    • continue


1. The if...else Statement

The if...else statement is used to execute code based on a condition. The basic syntax of an if...else statement is as follows:

sql
if (condition) {
   // Code to execute if condition is true
} else {
   // Code to execute if condition is false
}

The condition can be any expression that evaluates to a boolean value (true or false). If the condition is true, the code inside the if block is executed. If the condition is false, the code inside the else block is executed.

Here is an example:

arduino
#include <stdio.h>

int main() {
   int x = 10;

   if (x > 0) {
      printf("x is positive\n");
   } else {
      printf("x is negative or zero\n");
   }

   return 0;
}

In this example, we use an if...else statement to check if the value of x is positive or negative. If x is greater than zero, the program will print "x is positive." Otherwise, it will print "x is negative or zero."


2. The switch Statement

The switch statement is used to execute different blocks of code based on the value of a variable. The basic syntax of a switch statement is as follows:

arduino
switch (expression) {
   case value1:
      // Code to execute if expression is equal to value1
      break;
   case value2:
      // Code to execute if expression is equal to value2
      break;
   default:
      // Code to execute if expression does not match any of the cases
      break;
}

The expression can be any variable or expression that evaluates to an integral value. The cases represent the different possible values of the expression. If the expression matches one of the cases, the code inside that case block is executed. If there is no match, the code inside the default block is executed.

Here is an example:

arduino
#include <stdio.h>

int main() {
   int x = 2;

   switch (x) {
      case 1:
         printf("x is 1\n");
         break;
      case 2:
         printf("x is 2\n");
         break;
      case 3:
         printf("x is 3\n");
         break;
      default:
         printf("x is not 1, 2, or 3\n");
         break;
   }

   return 0;
}

In this example, we use a switch statement to check the value of x. If x is equal to 1, the program will print "x is 1." If x is equal to 2, the program will print "x is 2." If x is equal to 3, the program will print "x is 3." If x is not equal to any of these values, the program will print "x is not 1, 2, or 3."


3. The for Loop

The for loop is used to execute a block of code a fixed number of times. The basic syntax of a for loop is as follows:

css
for (initialization; condition; increment/decrement) {
   // Code to execute
}

The initialization is used to initialize a counter variable. The condition is used to check whether the loop should continue executing or not. Finally, the update statement is used to modify the counter variable before the next iteration of the loop starts.

Here's an example of using the for loop to print the first 10 positive integers:

c
#include <stdio.h>

int main() {
   int i;
   
   for(i=1; i<=10; i++) {
      printf("%d\n", i);
   }
   
   return 0;
}

In this example, we initialize the variable i to 1, and then we check if it's less than or equal to 10. If it is, we print the value of i using the printf() function and then increment i by 1. We continue this process until i is no longer less than or equal to 10.


4. The while Loop

The while loop is another type of loop in C that allows you to execute a block of code repeatedly while a condition is true. The syntax of the while loop is as follows:

c
while(condition) {
   // code to be executed
}

In this syntax, condition is the expression that is tested before each iteration of the loop. If the condition is true, the code inside the curly braces is executed. After each execution of the code, the condition is tested again, and the loop continues until the condition becomes false.

Here's an example of using the while loop to print the first 10 positive integers:

c
#include <stdio.h>

int main() {
   int i = 1;
   
   while(i <= 10) {
      printf("%d\n", i);
      i++;
   }
   
   return 0;
}

In this example, we initialize the variable i to 1, and then we use a while loop to print the value of i and increment i by 1 until i is no longer less than or equal to 10.


5. The do...while Loop

The do...while loop is similar to the while loop, but it guarantees that the code inside the loop is executed at least once, even if the condition is false. The syntax of the do...while loop is as follows:

c
do {
   // code to be executed
} while(condition);

In this syntax, the code inside the curly braces is executed first, and then the condition is tested. If the condition is true, the code is executed again, and the loop continues. If the condition is false, the loop exits.

Here's an example of using the do...while loop to print the first 10 positive integers:

c
#include <stdio.h>

int main() {
   int i = 1;
   
   do {
      printf("%d\n", i);
      i++;
   } while(i <= 10);
   
   return 0;
}

In this example, we initialize the variable i to 1, and then we use a do...while loop to print the value of i and increment i by 1 until i is no longer less than or equal to 10.


6. Loop Control Statements (break and continue)

C provides two loop control statements, break and continue, which allow you to control the flow of a loop.

1. The break statement is used to exit a loop immediately. When the break statement is encountered inside a loop, the loop is terminated, and the program continues with the next statement after the loop.

Here's an example that demonstrates the use of the break statement:

arduino
#include <stdio.h>

int main() {
   int i;
   
   for (i = 1; i <= 10; i++) {
      if (i == 5) {
         break;
      }
      printf("%d ", i);
   }
   
   printf("\nOut of loop.\n");
   
   return 0;
}

In this example, a for loop is used to print the numbers 1 to 10. However, when the value of i is 5, the break statement is executed, which causes the loop to terminate immediately. Therefore, only the numbers 1 to 4 are printed, and the program continues with the printf() statement outside the loop, which prints "Out of loop." to the console.

The output of this program is:

arduino
1 2 3 4 
Out of loop.

In addition to for loops, the break statement can also be used in while and do-while loops.

2. C also provides the continue statement, which is used to skip over the current iteration of a loop and continue with the next iteration.

Here's an example that demonstrates the use of the continue statement:

arduino
#include <stdio.h>

int main() {
   int i;
   
   for (i = 1; i <= 10; i++) {
      if (i == 5) {
         continue;
      }
      printf("%d ", i);
   }
   
   printf("\nOut of loop.\n");
   
   return 0;
}

In this example, a for loop is used to print the numbers 1 to 10. However, when the value of i is 5, the continue statement is executed, which causes the loop to skip over the current iteration and continue with the next iteration. Therefore, the number 5 is skipped, and the program continues to print the numbers 1 to 4 and 6 to 10.

The output of this program is:

arduino
1 2 3 4 6 7 8 9 10 
Out of loop.

In addition to for loops, the continue statement can also be used in while and do-while loops.

C Programming Basic Concepts << Previous || Next >> Arrays and Strings in C

Author
Vaneesh Behl
Passionately writing and working in Tech Space for more than a decade.

Comments

Post a Comment

Popular posts from this blog

What Role Graphic Design Services Play in Marketing

Image
Graphic design plays an essential part in today's marketing landscape and can provide an advantage for businesses. If you believe that graphic design is about images or drawings, then you're not right. Instead, it's about visuals proficient in solving problems using images. The vast majority of digital experts widely accept it as being one of the most important aspects of digital marketing because it helps marketers increase brand recognition and affect the decision-making process for their clients. In general, it is a representation of typography, symbols, colours, images, and symbols that contribute to the overall aesthetics of the communicated message. It is based on certain rules, trends, and concepts derived from a target audience's psychology studies. Get your work done by professional graphic design services 2022 .  Improve User Experience By in-Corporating Graphics In everything from brand identity to marketing via digital, any business can use graphic designs t...
Read more

Python Behave Tutorial: A Comprehensive Guide to Behavior-Driven Development (BDD)

Image
In this tutorial, we'll explain each and every aspect of Behavior Driven Development. This BDD Python tutorial will help you create and design your automation tests and framework. Table of Content 1. What is BDD? 2. What is Gherkin Language in BDD? 3. What is Behave in Python? 4. Installing and Setup Behave 5. Project Structure for Behave Python (BDD) 6. Feature Files, Step Functions and Other Files in Behave Feature File Step Functions Step Parameters Passing String Param from Feature File Passing Integer Param from Feature File environment.py file behave.ini file 7. Run Feature files in Behave Run a single feature file Run multiple feature files Generate JUNIT xml reports with behave Run feature files with Python suite file Upcoming Tutorials: 8. API Automation Testing with BDD Python (Behave) 9. Selenium Automation with BDD Python (Behave) 1. What is BDD? BDD stands for Behavior Driven Development. BDD is an agile process of development. It encourages non-technical or business t...
Read more

Mastering Locators in Selenium WebDriver: The Ultimate Guide with Examples

Image
Selenium is a popular open-source tool used for automating web browsers. It allows testers to write scripts in various programming languages such as Java, Python, C#, and Ruby to automate web applications. One of the critical aspects of Selenium automation is identifying web elements on a web page using locators. In this blog, we will discuss locators in Selenium and how to find them. Locators are nothing but a way to locate web elements on a web page. Selenium WebDriver provides a set of locators that can be used to identify web elements on a web page.  1. The various types of locators supported by Selenium WebDriver are: 1. ID Locator: This locator is the most common and efficient way to locate an element on a web page. Each web element on a page should have a unique ID. You can use the ID Locator to find an element using its ID. 2. Name Locator: The Name Locator is another way to locate an element using its name attribute. This is particularly useful when you want to loca...
Read more

14 Best Selenium Practice Exercises for Automation Practice

Image
  This page contains the list of Selenium Program exercises for automation practice. Your skills will definitely get a boost after solving these Selenium Practice Assignments. In these assignments, you will find the Sample Applications for Automation Testing . These Practice Assignments are designed in such a way that learners can enhance their automation skills. They also include multiple Sample Test Cases for Selenium along with step-by-step description which needs to be automated.  Reference links to  Selenium WebDriver Commands  for solutions are provided in the assignments. 10 Best Selenium Practice Exercises for Automation Practice Automate Amazon-like e-Comm Website with Selenium WebDriver In this self-learning project assignment, we'll automate all the major e-commerce website features with Selenium and Java. We'll automate Sign-up and login, search products, and purchase products for Amazon an e-commerce website. Automate GoDaddy.com Website features with Se...
Read more

Top 10 Websites for Interview Preparation: Features and Benefits for Job Seekers

Image
Preparing for a job interview can be a daunting task, but with the right resources and guidance, you can feel more confident and prepared. In this tutorial, we'll take a closer look at the top 10 sites for interview preparation, highlighting their unique features and how they can help you prepare for your next interview. Ambitionbox Ambitionbox is a website that offers company reviews and salary information, which can be beneficial for candidates who want to research the company they are interviewing for. Ambitionbox also has a dedicated section for interview preparation, where you can find articles on how to prepare for different types of interviews and common interview questions. Additionally, Ambitionbox has a section for interview experiences where candidates share their interview process with the company, which can give you an idea of what to expect. AceTheInterview AceTheInterview is a website that offers personalized interview coaching and mock interview sessions. The site...
Read more

Testing a Web Page/Website: Best Practices for Quality Assurance and Improved User Experience

Image
Testing a web page is an essential aspect of ensuring that it performs optimally and provides a seamless user experience. Testing involves a series of activities that are aimed at identifying and fixing issues with the web page, ensuring that it is accessible, responsive, and user-friendly. This post will discuss the various aspects of testing a web page, including the types of testing, the tools and techniques used, and the best practices for testing a web page. Table of Contents Types of Testing for Web Pages/ Website, Example, Checklist and Tools Functional Testing Perfomrance Testing Compatiblity Testing Usability Testing Security Testing Content Testing Accessibility Testing UI Testing Demo Websites for Practising Web Testing Best Practices for Testing Webpage / Website Conclusion Types of Testing for Web Pages/WebSite: There are several types of testing that can be performed on a web page. Some of the most common types of testing include: 1. Functional Testing This type of testi...
Read more

Top 10 Highly Paid Indian CEOs in the USA

Image
Top Indian CEOs in the USA Indian Americans have been making significant contributions to the US economy for decades. Many Indian-origin executives have reached the pinnacle of success in American corporations and hold some of the highest-paid positions in the country. In this post, we will take a look at the top 10 highly paid Indian-origin CEOs in the USA, their history, academics, salary, and net worth. 1. Sunder Pichai   Salary US$ 199.7 million Sundar Pichai is the CEO of Google and Alphabet Inc. Born in Tamil Nadu, India, Pichai grew up in a middle-class family and earned a Bachelor’s degree in Metallurgical Engineering from the Indian Institute of Technology in Kharagpur. He went on to earn a Master’s degree in Material Sciences and Engineering from Stanford University and an MBA from the Wharton School of the University of Pennsylvania. Pichai joined Google in 2004 and rose through the ranks to become CEO in 2015. His annual salary in 2021 was $2 million, and his net ...
Read more

17 Best Demo Websites for Automation Testing Practice

Image
We need demo websites for various purposes, like learning new tools and for automation testing practice. In this post, we cherry-picked some of the best websites to practice Selenium automation testing. This set of demo websites would help you to enhance your automation skills.  This post can help various people like,  Automation Testing learners, Experienced professionals, and even Automation Testing tutors/teachers. They all can benefit from these demo websites. Table of Contents 1. Techlistic Automation Practice Form 2. Amazon like Demo E-Commerce Website 3. Make My Trip like Travel Portal 4. Demo Automation Practice Web Table 5. Google.com 6. Demo Website for Handling Alerts 7. Way2Automation Demo 8. NewTours DemoAUT 9. The Demo Site 10. DemoQA 11. Para Bank 12. Orange HRM 13. Sauce Labs Demo E-Commerce Site 14. Demo Bank Demo Websites for API Automation Testing Practice 15. Restful Booker 16. Pet Store 17. Demo REST API Best Demo Websites for Automation Practice Let's...
Read more

Some Funny Conversations of QA and Developer over Bugs

Image
We all know the importance of humor in our life. And sometimes it comes our way when it's most unexpected and sometimes during stressful work hours and you just can't restrict yourself from sharing these funny moments with others.                                                   I am going to share some of the funniest experiences of the QA Engineers with developers. We IT professionals aware of the epic cold war between Developers and QA's. Developers never accept bug in their code and very often they give some illogical and funny excuses to back their buggy code. When some of the QA Engineers have been asked to share there funniest experiences /conversations with developers, see their responses: Suresh: In my recent project,...
Read more

Java Date Format Validation with Regular Expressions: A Step-by-Step Guide

Image
1. Introduction Validating date formats is an essential aspect of many software applications. It ensures that the user inputs a date in the correct format, reducing the risk of errors and inconsistencies in data. Regular expressions are a powerful tool for validating date formats. In this tutorial, we will explore how to validate date formats using regular expressions in Java.
Read more