If Else Statement in C
About this page
This is a tutorial in C Controls — syntax and concepts for if, if-else, and nested conditions. For runnable code, see the example programs: If Statement and If else.
Introduction
Decision control statements let your program choose different paths based on conditions. The if and if-else statements are the most fundamental decision constructs in C.
if Statement
Executes a block only when the condition is true (non-zero):
if (condition) {
/* statements */
}Example
#include <stdio.h>
int main(void) {
int marks = 75;
if (marks >= 40)
printf("Pass\n");
return 0;
}if-else Statement
Provides an alternative when the condition is false:
if (condition) {
/* true block */
} else {
/* false block */
}Example
#include <stdio.h>
int main(void) {
int num = 7;
if (num % 2 == 0)
printf("%d is even\n", num);
else
printf("%d is odd\n", num);
return 0;
}Sample Output
7 is oddif-else-if Ladder
Test multiple conditions in order:
#include <stdio.h>
int main(void) {
int score = 82;
if (score >= 90)
printf("Grade: A\n");
else if (score >= 80)
printf("Grade: B\n");
else if (score >= 70)
printf("Grade: C\n");
else
printf("Grade: F\n");
return 0;
}Sample Output
Grade: BNested if
An if inside another if:
int age = 20;
int hasLicense = 1;
if (age >= 18) {
if (hasLicense)
printf("Can drive\n");
else
printf("Need a license\n");
}Best Practices
Common Mistakes
Related Programs
Practice with our If Statement and If else example programs.
Frequently Asked Questions
What is the difference between if and if-else?
if executes a block only when the condition is true. if-else adds an alternative block that runs when the condition is false.
Can I omit braces for a single statement?
Yes, but braces are recommended — they prevent bugs when you add a second statement later.