Comparison Operators
Comparison operators are used to compare two values (or variables). This is important in programming, because it helps us to find answers and make decisions.
The return value of a comparison is either 1 or 0, which means true (1) or false (0). These values are known as Boolean values, and you will learn more about them in the Booleans and If..Else chapter.
In the following example, we use the greater than operator (>) to find out if 5 is greater than 3:
Example
int x = 5;
int y = 3;
printf("%d", x > y); // returns 1 (true) because 5 is greater than 3
A list of all comparison operators:
| Operator | Name | Example | Description | Try it |
|---|---|---|---|---|
| == | Equal to | x == y | Returns 1 if the values are equal | |
| != | Not equal | x != y | Returns 1 if the values are not equal | |
| > | Greater than | x > y | Returns 1 if the first value is greater than the second value | |
| < | Less than | x < y | Returns 1 if the first value is less than the second value | |
| >= | Greater than or equal to | x >= y | Returns 1 if the first value is greater than, or equal to, the second value | |
| <= | Less than or equal to | x <= y | Returns 1 if the first value is less than, or equal to, the second value |
Real-Life Examples
Comparison operators are often used in real-world conditions, such as checking if a person is old enough to vote:
Example
int age = 18;
printf("%d\n", age >= 18); // 1 (true), old enough to vote
printf("%d\n", age < 18); // 0 (false)
Another common use is checking if a password is long enough:
Example
int passwordLength = 5;
printf("%d\n", passwordLength >= 8); // 0 (false), too short
printf("%d\n", passwordLength < 8); // 1 (true), needs more characters
