Switch Enhancements in Java

• In this post, we are going to learn about recent enhancements to switch statement in Java.
• There are 4 enhancements to switch statement.

1. List of case constants
2. Switch expression
3. yield statement
4. case statement with arrow operator    

List of case constants

• If we want execute same block of code for some switch case constants , we write like below.

Output:

• The above example can be re-written using list of constants like below.

Switch expression, yield statement:

• Switch expression is simply switch statement which can return a value.
• We can return a value using yield keyword. We can write above using switch expression and yield keyword as below.

• We must add semicolon at the end of switch expression. Because it is treated a statement.
• We no need to write break statement because yield returns value and exit from switch expression. If we write break statement, we get compiler error.
• Normally default is optional for switch. But default is mandatory for switch expression.

Case statement  with arrow operator :

• We can use arrow operator after case statement in place of semicolon.

    case "JAN" :

    can be written as below.

    case "JAN" ->

• Arrow operator case statement can be in below three forms.

        case "JAN" -> expression;

        case "JAN" -> { block of statements}

        case "JAN" -> throw exception;

• Let's look at few examples using arrow operator .

• We can directly return value from case statement. We don't need to use yield keyword. 
• We don't need to use break because we exit from switch after returning value from switch.
• We must write default statement.

• When we use block , we must yield keyword to return value from switch expression.
• We don't need to use break statement. default statement is mandatory.

Conclusion:

These enhancements are really good addition to Java programming language. It optimizes the code. Thanks for reading . Happy Coding 😀.