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Lære Parameters and Return Values | Writing Functions in R
Functions and Functional Programming in R

bookParameters and Return Values

When you write functions in R, parameters allow you to make your code flexible and reusable. A parameter is a variable that you define in the function header, and it acts as a placeholder for values you will provide when calling the function. This means you can use the same function to perform similar tasks on different data, making your code more efficient and easier to maintain.

Note
Definition

In R, a parameter is the variable listed in a function's definition, while an argument is the actual value supplied to the function when it is called.

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multiply_by_two <- function(number) { return(number * 2) } multiply_by_two(5)
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In the multiply_by_two function, number is the parameter. When you call multiply_by_two(5), the value 5 is passed to the function and replaces the number parameter inside the function body. The function then returns 5 * 2, which is 10. You can call this function with any numeric value, such as multiply_by_two(10) or multiply_by_two(3.5), and it will return the input value multiplied by two. This demonstrates how parameters make functions adaptable to different inputs.

Return values from functions are not just for immediate display; you can assign them to variables or use them in further calculations. For example, you might write result <- multiply_by_two(7) to store the returned value in result, or even use the return value in an expression like multiply_by_two(7) + 5. This allows you to build more complex operations by combining function calls and other R expressions.

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describe_pet <- function(animal, name) { sentence <- paste("You have a", animal, "named", name) print(sentence) } describe_pet('dog', "Balto")
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When a function has more than one parameter, like describe_pet, you need to provide arguments in the correct order unless you use named arguments. In describe_pet("dog", "Max"), "dog" is assigned to animal and "Max" to name. Using meaningful parameter names, such as animal and name, makes your code more readable and easier to understand for anyone who reads it. Always choose names that clearly describe the expected input to avoid confusion and potential errors.

1. What is the difference between a parameter and an argument in R?

2. How many values can a function return in R?

3. Why is it important to use meaningful parameter names?

question mark

What is the difference between a parameter and an argument in R?

Select the correct answer

question mark

How many values can a function return in R?

Select the correct answer

question mark

Why is it important to use meaningful parameter names?

Select the correct answer

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bookParameters and Return Values

Sveip for å vise menyen

When you write functions in R, parameters allow you to make your code flexible and reusable. A parameter is a variable that you define in the function header, and it acts as a placeholder for values you will provide when calling the function. This means you can use the same function to perform similar tasks on different data, making your code more efficient and easier to maintain.

Note
Definition

In R, a parameter is the variable listed in a function's definition, while an argument is the actual value supplied to the function when it is called.

1234
multiply_by_two <- function(number) { return(number * 2) } multiply_by_two(5)
copy

In the multiply_by_two function, number is the parameter. When you call multiply_by_two(5), the value 5 is passed to the function and replaces the number parameter inside the function body. The function then returns 5 * 2, which is 10. You can call this function with any numeric value, such as multiply_by_two(10) or multiply_by_two(3.5), and it will return the input value multiplied by two. This demonstrates how parameters make functions adaptable to different inputs.

Return values from functions are not just for immediate display; you can assign them to variables or use them in further calculations. For example, you might write result <- multiply_by_two(7) to store the returned value in result, or even use the return value in an expression like multiply_by_two(7) + 5. This allows you to build more complex operations by combining function calls and other R expressions.

12345
describe_pet <- function(animal, name) { sentence <- paste("You have a", animal, "named", name) print(sentence) } describe_pet('dog', "Balto")
copy

When a function has more than one parameter, like describe_pet, you need to provide arguments in the correct order unless you use named arguments. In describe_pet("dog", "Max"), "dog" is assigned to animal and "Max" to name. Using meaningful parameter names, such as animal and name, makes your code more readable and easier to understand for anyone who reads it. Always choose names that clearly describe the expected input to avoid confusion and potential errors.

1. What is the difference between a parameter and an argument in R?

2. How many values can a function return in R?

3. Why is it important to use meaningful parameter names?

question mark

What is the difference between a parameter and an argument in R?

Select the correct answer

question mark

How many values can a function return in R?

Select the correct answer

question mark

Why is it important to use meaningful parameter names?

Select the correct answer

Alt var klart?

Hvordan kan vi forbedre det?

Takk for tilbakemeldingene dine!

Seksjon 1. Kapittel 3
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