## Example: Simple Calculator in R

```
# Program make a simple calculator that can add, subtract, multiply and divide using functions
add
```

**Output**

[1] "Select operation." [1] "1.Add" [1] "2.Subtract" [1] "3.Multiply" [1] "4.Divide" Enter choice[1/2/3/4]: 4 Enter first number: 20 Enter second number: 4 [1] "20 / 4 = 5"

In this program, we ask the user to choose the desired operation. Options 1, 2, 3 and 4 are valid.

Two numbers are taken from the user and a `switch`

branching is used to execute a particular function.

User-defined functions `add()`

, `subtract()`

, `multiply()`

and `divide()`

evaluate respective operations.