C If…Else
Conditions and If Statements
C supports the usual logical conditions from mathematics:
- Less than: a < b
- Less than or equal to: a <= b
- Greater than: a > b
- Greater than or equal to: a >= b
- Equal to a == b
- Not Equal to: a != b
You can use these conditions to perform different actions for different decisions.
C has the following conditional statements:
- Use if to specify a block of code to be executed, if a specified condition is true
- Use else to specify a block of code to be executed, if the same condition is false
- Use else if to specify a new condition to test, if the first condition is false
- Use switch to specify many alternative blocks of code to be executed
The if Statement
The if statement is used to check some given condition and perform some operations depending upon the correctness of that condition.
if (condition) {
// block of code to be executed if the condition is true
}
The else Statement
Use the else statement to specify a block of code to be executed if the condition is false.
if (condition) {
// block of code to be executed if the condition is true
} else {
// block of code to be executed if the condition is false
}
The else if Statement
Use the else if statement to specify a new condition if the first condition is false.
if (condition1) {
// block of code to be executed if condition1 is true
} else if (condition2) {
// block of code to be executed if the condition1 is false and condition2 is true
} else {
// block of code to be executed if the condition1 is false and condition2 is false
}
Short Hand If...Else (Ternary Operator)
The ternary operator consists of three operands. It can be used to replace multiple lines of code with a single line. It is often used to replace simple if else statements:
variable = (condition) ? expressionTrue : expressionFalse;