Understanding the If Statement:
- The if statement allows you to execute a block of code only if a specified condition is true.
- The basic syntax of an if statement is:
C
if (condition) {
// code to be executed if the condition is true
}- The condition is an expression that evaluates to either true or false.
Using Comparison Operators:
- Comparison operators are used to compare values in conditions.
- Common comparison operators in C include:
- == (equal to)
- != (not equal to)
- < (less than)
- > (greater than)
- <= (less than or equal to)
- = (greater than or equal to)
Using else statement:
- The else statement allows you to specify an alternative block of code to execute if the condition in the if statement is false.
- Example:
C
#include <stdio.h>
int main() {
int number;
printf("Enter a number: ");
scanf("%d", &number);
if (number > 0) {
printf("The number is positive.\n");
} else {
printf("The number is not positive.\n");
}
return 0;
}Using Else If Statement:
- The else if statement allows you to check multiple conditions sequentially.
- Here’s an example that categorizes numbers into positive, negative, or zero:
C
#include <stdio.h>
int main() {
int number;
printf("Enter a number: ");
scanf("%d", &number);
if (number > 0) {
printf("The number is positive.\n");
} else if (number < 0) {
printf("The number is negative.\n");
} else {
printf("The number is zero.\n");
}
return 0;
}Nesting If Statements:
- You can nest if statements within each other to create more complex conditions.
- Here’s an example that checks if a number is positive, even, and divisible by 3:
C
#include <stdio.h>
int main() {
int number;
printf("Enter a number: ");
scanf("%d", &number);
if (number > 0) {
if (number % 2 == 0) {
if (number % 3 == 0) {
printf("The number is positive, even, and divisible by 3.\n");
} else {
printf("The number is positive and even, but not divisible by 3.\n");
}
} else {
printf("The number is positive, but not even.\n");
}
} else {
printf("The number is not positive.\n");
}
return 0;
}