Switch in R

In R, a switch statement allows you to perform different actions based on a given value or condition. It is similar to an if-else statement but can be more concise for multiple possibilities.

The basic syntax for a switch statement in R is:

switch(EXPR, 
       CASE1 = expr1, 
       CASE2 = expr2, 
       ..., 
       default = expr.def)

where EXPR is the expression or variable to be evaluated, CASE1, CASE2, etc. are the possible values of EXPR and the corresponding expressions to be evaluated, and expr.def is the default expression to be evaluated if no other cases match.

Here is an example of how to use the switch statement in R:

# Creating a function that uses switch statement to determine the day of the week
get_day <- function(num) {
  return(switch(num,
                "1" = "Monday", 
                "2" = "Tuesday", 
                "3" = "Wednesday", 
                "4" = "Thursday", 
                "5" = "Friday", 
                "6" = "Saturday",
                "7" = "Sunday",
                "Invalid Day"))
}
# Testing the function for some values

get_day(1) # "Monday"

get_day(3) # "Wednesday"

get_day(10) # "Invalid Day"

In this example, a function called get_day() is defined that takes in a number as a parameter and uses the switch statement to return the corresponding day of the week as a string. If the input number is not valid, it returns "Invalid Day".

Another example of using the switch statement is to categorize the heights of people:

# Creating a function that uses switch statement to categorize the height of a person
categorize_height <- function(height) {
  category <- switch(TRUE,
                     height < 150 ~ "Short",
                     height >= 150 & height < 170 ~ "Average",
                     height >= 170 & height < 190 ~ "Tall",
                     height >= 190 ~ "Very Tall",
                     "Invalid Height")
  
  return(category)
}
# Testing the function for some values

categorize_height(140) # "Short"

categorize_height(160) # "Average"

categorize_height(185) # "Tall"

categorize_height(200) # "Very Tall"

categorize_height(50) # "Invalid Height"

In this example, a function called categorize_height() is defined that takes in a height as a parameter and uses the switch statement to categorize the height of the person into categories like "Short", "Average", "Tall", or "Very Tall". If the input height is not valid, it returns "Invalid Height".