expression是需要评估的表达式,value1、value2等是可能的常量值,当expression的值与某个case标签匹配时,执行相应的代码块。break语句用于跳出switch语句,防止执行后续的case代码块(即所谓的“贯穿”现象)。default标签是可选的,当没有case匹配时执行default代码块。 2. switch语句中case标签的要求 在Java中,switch语句的...
You could change your code to use anenumrather thanintconstants, but that brings another couple of different restrictions: Youmustinclude adefaultcase, even if you havecasefor every known value of theenum; seeWhy is default required for a switch on an enum? Thecaselabels must all be explic...
public static String lookup(int constant) { switch (constant) { case Foo.BAR: return "bar"; case Foo.BAZ: return "baz"; case Foo.BAM: return "bam"; default: return "unknown"; } } 但是,当我编译时,我在 3 个案例标签中的每一个上都收到 constant expression required 错误。 我知道编译...
14: Case outside of switch — 漏掉了case 语句 15: Case syntax error — Case 语法错误 16: Code has no effect — 代码不可能执行到 17: Compound statement missing{ — 分程序漏掉"{" 18: Conflicting type modifiers — 不明确的类型说明符 19: Constant expression required — 要求常量表达式 20: ...
然后,我想要一种基于常量获得相关字符串的方法: public static String lookup(int constant) { switch (constant) { case Foo.BAR: return "bar"; case Foo.BAZ: return "baz"; case Foo.BAM: return "bam"; default: return "unknown"; }} 但是,当我编译时,我会得到一个constant expression required三个...
constant expression required privatevoidTest(inttype){switch(type){caseColorType.GREEN.getCode():break;caseColorType.RED.getCode():break;caseColorType.ORANGE.getCode():break;default:break; } } 解决方式 枚举值不是常量, 而case后面只能跟常量. ...
It throws a “Constant expression required” error when it’s compiled and it points to the case p: line, however, it also throws it for f: if I switch them so I must be doing something completely off. 解决方案 Yes, a case expression has to be a constant (or an enum constant name...
You can't apply logical complement ! to a numeric expression, nor can you apply a negation operator - to a boolean expression. int x = -5; booean y = !true; 2) Increment ++ and Decrement Operators -- pre-increment and pre-decrement operators:new value returned; ...
Pattern.CaseInsensitive Field Reference Feedback Definition Namespace: Java.Util.Regex Assembly: Mono.Android.dll Caution This constant will be removed in the future version. Use Java.Util.Regex.RegexOptions enum directly instead of this field. Enables case-insensitive matching. C# 複製 [...
安全问题其实是很多程序员想了解又容易忽略的问题,但需要我们重视起来,提高应用程序的安全性。常出现的安全问题包括,程序接受数据可能来源于未经验证的用...