Switch Case Java

With the help of the Java programming language's switch case statements, programmers can easily build complicated decision-making logic. In this section, we'll look at the syntax of switch case statements, discuss why they're better than if-else statements, and give some usage examples.

Syntax

The basic syntax of switch case statements in Java is as follows:

The code block that corresponds to the value of the expression is then executed by the switch statement once the expression is evaluated as its argument. Case statements are employed to contrast the expression's value with various potential values. The code block corresponding to that case statement is executed if the value of the expression matches one of the case statements. The code block contained within the default statement is performed if any of the case statements do not match.

The switch statement's code block can be stopped running by using the break statement. Unexpected behaviour will occur if the break statement is not utilised since the execution will "slip through" to the following case statement.

Advantages of switch case statements

Switch case statements have several advantages over traditional if-else statements:

1. Clarity: Switch case statements can make the code easier to read and understand, especially when dealing with a large number of possible values.
2. Efficiency: Switch case statements can be more efficient than if-else statements because the Java compiler can optimize the generated code for switch case statements.
3. Maintainability: Switch case statements can make the code easier to maintain, as it is easy to add or remove case statements without affecting the rest of the code.

Now that we understand the syntax and advantages of switch case statements, let's take a look at some examples of their usage.

Example 1: Simple switch case statement

Output:

Day of week: 3
Day name: Wednesday

In this example, we declare an integer variable dayOfWeek and initialize it with the value 3. We then use a switch case statement to determine the day of the week based on the value of dayOfWeek. Since dayOfWeek is initialized to 3, the code block within the case 3: statement is executed, and the value of dayName is set to "Wednesday".

Example 2: Switch case statement with fall-through

Output:

Month number: 2
Month name: Spring

In this example, we declare an integer variable `month` and initialize it with the value 2. We use a switch case statement to determine the season based on the value of `month`. The `case 2:`, `case 3:`, and `case 4:` statements all have the same code block, so they will all result in the `monthName` variable being set to "Spring". This is an example of fall-through, where the execution falls through from one case statement to the next.

Example 3: Switch case statement with strings

Output:

Fruit: apple
Fruit color: red

In this illustration, we declare a string variable called "fruit" and set its first value to "apple". Based on the value of "fruit," we utilise a switch case statement to decide the hue of the fruit. The code block contained within the "case "apple":" statement is run because "fruit" is initialised to "apple," changing the value of "fruitColor" to "red."

In conclusion, Java's switch case statements are a potent tool that can make code simpler to comprehend, more effective, and simpler to maintain. They are especially helpful when there are a lot of potential values or when the values are distinct and simple to compare. By substituting if-else expressions with switch case statements, Code can be written by developers in a clearer, shorter, and more comprehensible manner.