switch in r

In R, the switch() function is used to select one of several alternatives based on a provided expression. It takes in an expression and a set of cases, and returns the value corresponding to the first matching case.

Here's an explanation of each step involved in using the switch() function:

1. Provide an expression: The switch() function requires an expression as its first argument. This expression is evaluated, and its value is used to determine which case to select.

2. Define the cases: The subsequent arguments to switch() are the cases. Each case consists of a value to match against the expression and the corresponding value to return if the case is a match. The cases are defined using the following format: case_value = return_value.

3. Evaluate the expression: The switch() function evaluates the provided expression and checks it against each case value in the order they are defined.

4. Match the expression with a case: Once the expression matches a case value, the corresponding return value is returned by the switch() function.

5. Default case: If none of the case values match the expression, the default value is returned. The default value is specified by using the argument default = return_value after the cases.

6. Return the selected value: The switch() function returns the value corresponding to the first matching case or the default value if no match is found.

That's it! The switch() function in R allows for conditional selection of values based on an expression, providing a convenient way to handle different scenarios in your code.