Loop in C: A simple guide with examples

Loops are an indispensable tool in programming, which allows us to execute a piece of code repeatedly. They can perform a variety of tasks, from simple calculations to complex data processing.

In c programming, we have three main loop types: for , while , and do-while . Let's explore them with examples.

for loop

When we know exactly how many times we want to repeat a piece of code, for loop is the default choice. It's like setting a timer for our code to run a specific number of times.

 // syntax

for (initialization; condition; increment/decrement) {
  // code to be executed in each iteration
}

// example

#include <stdio.h>

int main() {
  for (int i = 1; i <p>In this example, for loops to print numbers from <em>1 to 5</em> . Initialization ( <em>int i = 1;</em> ) Sets the starting value of the counter variable <em>i</em> . Condition ( <em>i  ) specifies that the cycle should continue as long as <em>i is less than or equal to 5</em> . After each iteration, the increment ( <em>i</em> ) <em>increases the value of</em> <em>i</em> by 1.</em></p>
<h3 id="em-While-em-loop"> <em>While</em> loop</h3>
<p> <em>While</em> loop is like a conditional loop. As long as the condition remains true, it keeps spinning (execute code block).<br></p>
<pre class="brush:php;toolbar:false"> // syntax
while (condition) {
  // code to be executed repeatedly
}

// example
#include <stdio.h>

int main() {
  int i = 1;
  while (i <p>This <em>while</em> loop implements the same result as <em>the for</em> loop above. It prints numbers from <em>1 to 5</em> , but the counter variable <em>i</em> is initialized outside the loop structure and increments.</p>
<h3 id="em-do-while-em-loop"> <em>do-while</em> loop</h3>
<p> <em>The do-while</em> loop insists on executing the code block at least once, even if the condition is initially false.<br></p>
<pre class="brush:php;toolbar:false"> // syntax
do {
  // Code to be executed repeatedly
} while (condition);

// example
#include <stdio.h>

int main() {
  int i = 6; // Notice i is initialized to 6
  do {
    printf("%d ", i);
    i ;
  } while (i <p>Even if the condition <em>i  is false from the beginning, <em>the do-while</em> loop still executes the code block once, printing <em>the value of i (i.e. 6)</em> .</em></p>
<h3 id="Application-of-loops"> Application of loops</h3>
<p> Loops are very versatile and have a wide range of applications in programming:</p>
<ul>
<li> Repeat tasks: Automatically perform repetitive operations, such as printing a series of numbers, processing data in an array, or reading user input until a specific condition is met.</li>
<li> Iterative data structures: Access and manipulate elements in arrays, lists, or other data structures.</li>
<li> Implementing algorithms: Loops are the basic building blocks of many algorithms, such as sorting, searching, and graph traversal.</li>
<li> Create simulations and games: Simulate real-life scenes or create game logic involving repeated actions or events.</li>
</ul>
<p> Finally, since loops are the foundation of programming, understanding loops in C will prepare you for learning other languages ​​such as python, javascript, and java.</p></stdio.h>

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