Check if a Number is Positive, Negative or Zero

In this example, a number entered by the user is checked whether it’s a positive number or a negative number or zero.

To understand this example, you should have the knowledge of following R programming topics:


Example: Check Positive, Negative or Zero

# In this program, we input a number check if the number is positive or negative or zero 
num = as.double(readline(prompt="Enter a number: "))
if(num > 0) {
print("Positive number")
} else {
if(num == 0) {
print("Zero")
} else {
print("Negative number")
}
}

Output 1

Enter a number: -9.6
[1] "Negative number"

Output 2

Enter a number: 2
[1] "Positive number"

A number is positive if it is greater than zero.

We check this in the expression of if. If it is FALSE, the number will either be zero or negative.

This is also tested in subsequent expression.