switch case in java

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The switch statement in Java is a control flow statement that allows you to test a variable or an expression against multiple cases. It's similar to the if-else statement, but it can be a more convenient and efficient way to handle multiple conditions. The basic structure of a switch statement is as follows: 

The expression is the variable or expression that you want to test. The case statement is followed by a value or an expression, and the code that follows the case statement will be executed if the expression matches that value. The break statement is used to exit the switch statement and prevent the execution of the next case. 
 Here's an example of a switch statement in Java: 


In Java 8, the switch statement was enhanced to support lambda expression as well. It allows you to use a functional interface inside the case statement, which makes the switch statement more powerful. Here's an example of how you can use a lambda expression in a switch statement in Java: 


In this example, the variable "day" is used to determine which lambda expression will be run inside the switch statement. This can be useful when you have multiple cases that need to perform similar actions. 

With Java 14 and above, you can also use a switch expression which is a more compact and expressive way of writing a switch statement. It returns a value as the result of the switch, as opposed to the traditional switch which does not return a value. Here's an example of a switch expression in Java: 


This kind of switch expression returns a value of the corresponding case, in this case "Wednesday" and it's assigned to the variable dayName. 

As a new programmer, it's important to understand the different ways you can use a switch statement in Java. The use of lambda expression and switch expression makes the code more concise and readable. It also allows you to perform more complex logic and functional programming inside the switch statement.

It's important to note that when using lambda expression in a switch statement, the cases must match the type of the switch expression, and in case of switch expression, it's mandatory to have a default case.

It's also important to use the break statement, or the yield statement in case of switch expression, to exit the switch statement and prevent the execution of the next case. Otherwise, the code in all the subsequent cases will be executed, even if the condition is not true.

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