Switch Statements is used to test the equality against a list of values each values is known as a case and the variable being switched on is checked for each case. It is used in place of long if statement which compares a variable with several values.
Switch case in R is a multi-way branch statement which provide easy ways to execute different parts of code. Its code is based on the value of the expression.
It is a selection control mechanism which allows the value of an expression to change the control flow of program execution. It follows the approach of mapping and searching over a list of values.
Some important points:
- In case if there is more than one match then the first match element is used.
- Unnamed case is used if no matched case is found.
- No default argument case is available
Syntax
switch(expression, case1, case2, case3, Case4....)Example
x<-2
y<-switch(
x,
"Monday",
"Tuesday",
"Wednesday",
"Thursday",
"Friday"
)
print(y)Output: [1] "Tuesday"