Switch case statements in Java - Tutorial for Beginners

Switch case statements in Java - Tutorial for Beginners

In this video, we will talk about switch case structures.
In our previous videos, we said that there are three types of selection control structures in Java.
We talked about the first two of these selection control, which are the if and the if … else statements

Now, the third selection control structure is called the Switch case structure
One of its particularities is that it does not require the evaluation of a logical expression as compared to the if … else statements

The Switch case structure allows the computer to choose from multiple alternatives or options

Here on the screen, is the syntax of a switch case statement

char grade = ‘A’

switch (grade)
{
case 'A':
System.out.println("The grade is A.");
System.out.println("You are a first class student");
break;
case 'B':
System.out.println("The grade is B.");
break;
case 'C':
System.out.println("The grade is C.");
break;
case 'D':
System.out.println("The grade is D.");
break;
case 'F':
System.out.println("The grade is F.");
break;
default:
System.out.println("The grade is invalid.");
}

Let me explain the various elements in this statement
First, let’s note that the words switch, case, break, and default in this statement are what we call in Java reserved words or keywords

Secondly, just after the keyword switch, is what we call the selector
In a switch structure, the selector is evaluated first and its value is used to determine which action statements are selected for execution.
The selector can be a variable or an expression
Also, the value returned by the selector must only be of type int, byte, short or char
So, if the selector is an expression, then it must return an integral value

Next, we have the keyword case and right after the keyword there is a value
The value is making reference to the whatever value the selector may return
Note that a specific case value must appear only once in a switch structure
We cannot have two case values that are the same

Following the case value, we have a statement
This statement will be executed if the value of the selector is equal to the case value
We can have one or more statements associated with a case value
So, we do not need to use curly braces to turn multiple statements into a single compound statement

Next, the keyword break is used to exit a switch case structure
I will talk to you in much more details about the importance of this keyword in the next video

The keyword default is also not compulsory and it is used to determine the statements that will be executed whenever the selector value does not match any of the case values

So basically, in our example here is what is going to happen

We have declared a variable grade of a type character
That variable grade is used as the selector in our switch case structure

Whenever the value stored in the selector grade matches against a specified case value, then the appropriate action statement associated with that case value is executed

When we store the character ‘A’ in the grade then we will get the first action statement in the console
If we store the character ‘B’ then the second action statement will execute
If we store the character ‘C’ then the third action statement will execute
If we store the character ‘D’ then the fourth action statement will execute
If we store the character ‘F’ then the fifth action statement will execute

But if we store a character such as ‘M’, that is not corresponding to any of the case values, then the default action statement will execute

Alright, guys, that’s it about the Switch case structure in the next video I will talk to you about the importance of using the break statement function in a switch case control strucuture

Thanks for viewing, I hope this video was informative.
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Let’s meet in another video.

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