case语句

Case statements are often used in programming when dealing with certain tasks. It's a powerful mechanism that allows programmers to create more automated and efficient codes.
A case statement is a statement that will be executed based upon the value of an expression. The expression being evaluated could be a variable or some other type of expression. The case statement will check the value of the expression, and then execute one of several code blocks depending on the value.
For example, the following code will print "Hello, World!" if the value of the variable "x" is 2:
case x when 2 puts "Hello, World!" end
The case statement is also useful for dealing with multiple conditions. In this case, you can provide a series of different code blocks for each condition. For example, the following code will print "Hello, World!" if the value of the variable "x" is 2, 3, or 4:
case x when 2, 3, 4 puts "Hello, World!" end
Finally, the case statement can be used to create complex and sophisticated programs. In this case, the case statement can be used to create a program that can handle different scenarios depending on specific input. For example, a program can be written that can handle different types of payment methods based on user input.
Overall, case statements are a powerful tool that can be used to create more automated and efficient codes. They can be used to simplify complex scenarios, and they can also be used to create more sophisticated programs.