The if-else statement is a control structure that allows you to test a condition and act on it depending on whether it's true or false. The syntax for an if-else statement is as follows:
if (condition) {
# do something if condition is true
} else {
# do something if condition is false
}
For example, the following code will print "The number is greater than 5" if the variable `x` is greater than 5, and "The number is less than or equal to 5" if it's not:
x <- 10
if (x > 5) {
print("The number is greater than 5")
} else {
print("The number is less than or equal to 5")
}
The else clause is optional. If you don't include it, the code will simply skip to the next line if the condition is false.
You can also have multiple if-else statements, with each one testing a different condition. For example, the following code will print "The number is positive" if `x` is greater than 0, "The number is zero" if `x` is equal to 0, and "The number is negative" if `x` is less than 0:
x <- -5
if (x > 0) {
print("The number is positive")
} else if (x == 0) {
print("The number is zero")
} else {
print("The number is negative")
}
