# Define the quicksort function
quicksort <- function(arr) 
{
 if (length(arr) <= 1) 
 {
 return(arr)
 }

pivot <- arr[1]
smaller <- arr[arr < pivot]
equal <- arr[arr == pivot]
larger <- arr[arr > pivot]

return(c(quicksort(smaller), equal, quicksort(larger)))
}

# Example usage
input_array <- c(7, 2, 1, 6, 8, 5, 3, 4)
sorted_array <- quicksort(input_array)
cat("Sorted array:", sorted_array, "\n")

Default Values in Functions:

In R, default parameter values can be assigned to function arguments, which enables you to call a function without explicitly providing a value for those parameters in certain cases. This feature is especially useful when you want to provide a commonly used value for a function argument, but still allow the flexibility for the user to override it if needed.

Syntax for Defining Default Parameter Values:

function_name <- function(arg1 = default_value1, arg2 = default_value2, ...) 
{
  # Function body
}

In the function declaration, you can assign default values (e.g., default_value1, default_value2) to function arguments (e.g., arg1, `arg2), making them optional when calling the function.

Example of Default Values in a Function:

# Define a function with default parameter value
greet_user <- function(name = "Guest") {
  cat(paste("Hello,", name, "Welcome to our site!"))
}

# Call the function with default value
greet_user()  # Output: Hello, Guest. Welcome to our site!

# Call the function with a specific value
greet_user("Alice")  # Output: Hello, Alice. Welcome to our site!

In this example:

• The greet_user function is declared with the name parameter having a default value of “Guest”.
• When the function is called without providing a value for name, it uses the default value “Guest”.
• When the function is called with a specific name (e.g., “Alice”), it overrides the default value.

Return Statements in Functions:

In R, the return statement is used to explicitly specify the value that a function should return when it is called. Although it is not always necessary to use the return statement (the last expression evaluated before the end of a function is automatically returned), it helps in making the function’s intention clearer.

Syntax for Return Statement:

function_name <- function(arg1, arg2, ...) 
{
  # Function body
  return(output_value)  # Optional: Explicit return statement
}

The return statement can be used anywhere within the function body to return a specific value. Once a return statement is executed, the function exits and the specified value is returned.

Example of Return Statement in a Function:

# Define a function with a return statement
calculate_sum <- function(a, b) {
  sum <- a + b  # Calculate the sum
  return(sum)  # Return the calculated sum
}

# Call the function and store the returned value
result <- calculate_sum(3, 5)
cat("The sum is:", result)  # Output: The sum is: 8

In this example:

• The calculate_sum function calculates the sum of two numbers (a and b) and uses the return statement to explicitly return the calculated sum.
• When the function is called with arguments 3 and 5, the returned sum is stored in result and then printed.