- C Introduction
- C - Features
- C - Applications
- C - Preprocessor
- C - Preprocessor Directives
- C - Type Definitions
- C - Function Prototypes
- C - Header Files and Libraries
- C - Main Function
- C Program Elements
- C - Datatypes
- C - Constants
- C - Operators
- C - Assignment Operator
- C - Arithmetic Operator
- C - Relational Operator
- C - Sample Program to illustrate C relational operator
- C - Logical Operator
- C - Sample Program to demonstrate logical operators
- C - Increment and Decrement Operator
- C - Sample Program to illustrate pre increment
- C - Sample Program to illustrate post increment
- C - Bitwise Operator
- C - Sample Program to illustrate bitwise Operator
- C - Conditional Operator
- C - Comma Operator
- C - Sizeof Operator
- C - Typecast Operator
- C - Operator Precedence and Associativity
- C - Identifiers
- C - Keywords
- C Statements
- C - if-else statement
- C - else-if ladder statement
- C - Switch statement
- C - Sample Program to illustrate switch statement
- C - While Statements
- C - Sample Program to illustrate while loop
- C - do-while Statement
- C - for Statement
- C - Sample Program to illustrate for-loop
- C - Break statement
- C - Continue statement
C - While Statements
While Statements in C
Introduction
The while loop in C programming is a control flow statement that allows code to be executed repeatedly based on a given condition. The while loop is one of the most commonly used looping structures, as it repeats a block of code as long as the specified condition is true.
Syntax of While Statement
The syntax of the while loop is as follows:
while (condition) {
// Block of code to be executed
}
Here:
- condition: The condition is evaluated before each iteration. If the condition evaluates to true, the block of code inside the loop is executed. If the condition is false, the loop terminates and the program continues with the code after the loop.
- block of code: The block of code will be executed repeatedly as long as the condition evaluates to true.
Working of While Loop
The while loop checks the condition before executing the block of code. If the condition is true, the code inside the loop is executed. After executing the code, the condition is evaluated again. If the condition is still true, the code will execute again. This process continues until the condition becomes false, at which point the loop terminates.
Flowchart of a While Loop
Here’s a simple flowchart to illustrate how the while loop works:
- Step 1: Check the condition.
- Step 2: If the condition is true, execute the block of code.
- Step 3: After execution, check the condition again.
- Step 4: Repeat the process until the condition becomes false.
Example of a While Loop
The following example demonstrates the use of the while loop to print numbers from 1 to 5:
#includeint main() { int i = 1; // While loop to print numbers from 1 to 5 while (i <= 5) { printf("%d\n", i); i++; // Increment the value of i } return 0; }
Explanation of the Example
- The while loop checks if i <= 5.
- Since i starts at 1, the condition is true, and the loop executes the block of code.
- The value of i is printed, and then it is incremented by 1 (i++).
- The condition i <= 5 is checked again. This process repeats until i becomes 6, at which point the condition evaluates to false and the loop terminates.
Types of While Loops
1. Basic While Loop
The basic while loop is the most straightforward form, where the condition is checked before each iteration, as shown in the earlier example.
2. Do-While Loop
A variation of the while loop is the do-while loop. The difference is that the condition is checked after the block of code is executed, meaning that the code will run at least once even if the condition is false. The syntax of the do-while loop is as follows:
do {
// Block of code to be executed
} while (condition);
In this case, the block of code is executed first, and then the condition is checked. If the condition is true, the loop continues.
The while loop is a fundamental control flow structure in C programming that allows you to execute a block of code repeatedly based on a condition. It is versatile, easy to use, and effective when the number of iterations is not predetermined. However, care should be taken to avoid infinite loops by ensuring the condition eventually becomes false.
