# 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.