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Java switch case explanation and sample program.

Introduction :-

       Today we shall , see another topic about the conditional statements which is the switch case. So in the post there will be the a sample program  and the same sample program's download link is provided . Feel free to have changes in the code and if you wish to share the modified code , share it in the comment section .

What is the switch case basically ?

    Switch case is similar to the if-else only the change is that it will change according to the condition in the switch block there will be multiple case which are will evaluate according to the switch condition.

What is the syntax of the switch case ?

Syntax :-

switch(expression)
{
   // case statements
   // values must be of same type of expression
   case value1 :
      // Statements
      break; // break is optional
   
   case value2 :
      // Statements
      break; // break is optional
   
   // We can have any number of case statements
   // below is default statement, used when none of the cases is true. 
   // No break is needed in the default case.
   default : 
      // Statements
}

What are the rules of the switch case ?

  • Duplicate case values are not allowed.
  • The value for a case must be the same data type as the variable in the switch.
  • The value for a case must be a constant or a literal.Variables are not allowed.
  • The break statement is used inside the switch to terminate a statement sequence.
  • The break statement is optional. If omitted, execution will continue on into the next case.
  • The default statement is optional, and can appear anywhere inside the switch block. In case, if it is not at the end, then a break statement must be kept after the default statement to omit the execution of next case statement.

Sample Program about the switch case:-

Code :-
public class Test { 
    public static void main(String[] args) 
    { 
        int day = 5; 
        String dayString; 
  
        // switch statement with int data type 
        switch (day) { 
        case 1: 
            dayString = "Monday"; 
            break; 
        case 2: 
            dayString = "Tuesday"; 
            break; 
        case 3: 
            dayString = "Wednesday"; 
            break; 
        case 4: 
            dayString = "Thursday"; 
            break; 
        case 5: 
            dayString = "Friday"; 
            break; 
        case 6: 
            dayString = "Saturday"; 
            break; 
        case 7: 
            dayString = "Sunday"; 
            break; 
        default: 
            dayString = "Invalid day"; 
            break; 
        } 
        System.out.println(dayString); 
    } 
} 

Note :-    Now save the code as "Test.java" and run using cmd or the IDE.

OUTPUT:-
Friday

Download link for the code .
     
        So if find this post useful then share it with your friends and try to comment for any improvement in the post .


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