int i = switch (day) { case MONDAY -> { System.out.println("Monday"); // ERROR! Block doesn't contain a yield statement } default -> 1;};case2: 以下代码无法编译，因为缺失yield语句。int i = switch (day) { case MONDAY, TUESDAY, WEDNESDAY: yield 0; default...
privatestaticvoidsqlStatement(){Stringsql="""SELECT id, firstName, lastName\s\FROM EmployeeWHERE departmentId = "IT" \ORDER BY lastName, firstName""";System.out.println(text);} 2.2 改进的Switch语句 在Java 17中,对Switch语句进行了进一步的改进,可以解决忘记写break关键字导致的bug问题。 Switch表...
privatestaticvoidsqlStatement(){String sql="""SELECTid,firstName,lastName\s\FROMEmployeeWHEREdepartmentId="IT"\ORDERBYlastName,firstName""";System.out.println(text);} 改进的 Switch 语句 Switch 表达式将允许您从 switch case 返回值,并在赋值中使用这些返回值。Java 允许使用运算符->(箭头)而不是:(...
private static void sqlStatement() { String sql = """ SELECT id, firstName, lastName\s\ FROM Employee WHERE departmentId = "IT" \ ORDER BY lastName, firstName"""; System.out.println(text); } 改进的 Switch 语句 Switch 表达式将允许您从 switch case 返回值,并在赋值中使用这些返回值。Ja...
1. Switch Statements 1.1. Syntax The general form of a switch statement is – switch(expression){caselabelOne:statements;break;caselabelTwo:statements;break;caselabelThree:statements;break;default:statements;} The expression value must be one of the following 6 types: ...
In the following code, the switch statement has repetitive break and assignment statements in case labels, which adds noise to the code. The default fall-through in switch branches can sneak in a logical error. For example, if we delete the break statement for case labelSTRAW, it results in...
The switch statement allows us to execute a block of code among many alternatives. Syntax: switch (expression) { case value1: // code break; case value2: // code break; ... ... default: // default statements } How does the switch-case statement work? The expression is evaluated once...
intday=3;switch(day){case1:System.out.println('Monday');break;case2:System.out.println('Tuesday');break;// ...}#Output:#'Tuesday' Java Copy In this example, we have a switch statement that checks the value of the variableday. Depending on the value, it executes a different code blo...
2. Switch expression When using a switch expression in Java 14, you don’t have to use thebreakkeyword to break out of the switch statement or usereturnkeyword on each switch case to return a value; instead, you can return the entire switch expression. This enhanced switch expression makes...
其中,switch、case、default、break 都是 Java 的关键字。 1)switch 表示“开关”,这个开关就是 switch 关键字后面小括号里的值,小括号里要放一个整型变量 或字符型变量。表达式必须为 byte,short,int,char 类型。 Java7增强了 switch 语句的功能,允许 switch 语句的控制表达式是 java.lang.String 类型的变量或...