Basically, the expression can be byte, short, char, and int primitive data types. switch(expression) { case x: // code block break; case y: // code block break; default: // code block} This is how it works: The switch expression is evaluated once. Before we discuss about break statement, Let’s have a look at the example below where I am not using the break statement:In the above program, we have passed integer value 2 to the switch, so the control switched to the case 2, however we don’t have break statement after the case 2 that caused the flow to pass to the subsequent cases till the end. switch case 语句有如下规则： switch 语句中的变量类型可以是： byte、short、int 或者 char。从 Java SE 7 开始，switch 支持字符串 String 类型了，同时 case 标签必须为字符串常量或字面量。 switch 语句可以拥有多个 case 语句。每个 case 后面跟一个要比较的值和冒号。 If no break appears, the flow of control will Compile and run the above program using various command line arguments. You can have any number of case statements within a switch. A Javaswitchstatement enables you to select a set of statements to execute based on the value of some variable. We will first see an example without break statement and then we will discuss switch case with break The syntax of Switch case statement looks like this – switch (variable or an integer expression) { case constant: //Java code ; case constant: //Java code ; default: //Java code ; } Switch Case statement is mostly used with break statement even though it is optional. The solution to this problem is break statementBreak statements are used when you want your program-flow to come out of the switch body. The variable used in a switch statement can only be integers, convertable integers (byte, short, char), strings and enums.You can have any number of case statements within a switch.
If There is not matched then it will return the default statement. A switch works with the byte, short, char, and int primitive data types. The syntax of Switch case statement looks like this –First the variable, value or expression which is provided in the switch parenthesis is evaluated and then based on the result, the corresponding case block is executed that matches the result.Break statement is optional in switch case but you would use it almost every time you deal with switch case. It can have any integer value after case keyword. Each case is followed by the value to be compared to and a colon. The Java switch expression must be of byte, short, int, long (with its Wrapper type), enums and string. This is in effect somewhat similar to a Java ifstatement, although the Java switchstatement offers a somewhat more compressed syntax, and slightly different behaviour and thus possibilities. The switch statement is a multi-way branch statement. Also, case doesn’t need to be in an ascending order always, you can specify them in any order based on the requirement.2) You can also use characters in switch case.
for example –3) The expression given inside switch should result in a constant value otherwise it would not be valid.4) Nesting of switch statements are allowed, which means you can have switch statements inside another switch. However nested switch statements should be avoided as it makes program more complex and less readable. A Java switch statement is matched case (condition) and execute statement for that. It provides an easy way to dispatch execution to different parts of code based on the value of the expression. Whenever a break statement is encountered in the switch body, the execution flow would directly come out of the switch, ignoring rest of the casesLet’s take the same example but this time with break statement.Now you can see that only case 2 had been executed, rest of the cases were ignored.1) Case doesn’t always need to have order 1, 2, 3 and so on. Each case statement can have a break statement which is optional. The following rules apply to a switch statement − The variable used in a switch statement can only be integers, convertable integers (byte, short, char), strings and enums. When control reaches to the break statement, it jumps the control after the switch expression. It also works with enumerated types (discussed in Enum Types ), the String class, and a few special classes that wrap certain primitive types: Character , Byte , Short , and Integer (discussed in Numbers and Strings ). In the Switch statement, using passing value and then this value will go down the list of the case to find matched one. Each case is followed by the value to be compared to and a colon.The value for a case must be the same data type as the variable in the switch and it must be a constant or a literal.When the variable being switched on is equal to a case, the statements following that case will execute until a Not every case needs to contain a break. This will produce the following result −