What is the usage of Java switch?

The switch statement in Java is used to execute different code blocks based on different conditions. The basic syntax of the switch statement is "switch (expression) {case value1:// execute code block 1break; case value2:// execute code block 2break;...default:// execute default code block break;}".

#The switch statement in Java is used to execute different blocks of code based on different conditions. It can replace longer if-else if-else statements, making the code more concise and readable.

The basic syntax of the switch statement is as follows:

switch (expression) {case value1:// 执行代码块1break;case value2:// 执行代码块2break;
...default:// 执行默认代码块break;
}

• expression is the expression that needs to be judged, usually an integer, character or enumeration type.

• Each case is followed by a constant value or a specific expression, indicating the value that needs to be matched.

• When the value of expression matches a certain case, the corresponding code block will be executed.

• If a case matches successfully, all subsequent code blocks will be executed until the break statement or switch statement is encountered.

• If all cases do not match, the default code block (optional) will be executed.

• The break statement is used to jump out of the switch statement and avoid executing other case code blocks.

• If there is no break statement or return statement, after a successful match, the code block of the next case will continue to be executed until the break statement or switch statement is encountered.

The following is an example of using the switch statement:

int day = 1;
String dayString;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); // 输出 "Monday"

In the above example, based on the value of day, the switch statement matches case 1 , and execute the corresponding code block and assign dayString to "Monday". The final output is "Monday".

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