这称之为“fall through”,意思是:如果case语句后面不加break,就依次执行下去,以满足某些特殊情况的要求。但实际上,这是一个非常不好的特性,因为几乎所有的case都需要以break结尾。在大多数情况下,你不希望因这个缺省的行为而不得不加上一条额外的break语句来改变它。
3.Fallthrough Swift 语言中的 switch 不会从上一个 case 分支落入到下一个 case 分支中。相反,只要第一个匹配到的 case 分支完成了它需要执行的语句,整个 switch 代码块完成了它的执行。相比 之下,C 语言要求你显示的插入 break 语句到每个 switch 分支的末尾来阻止自动落入到下 一个case分支中。Swift语言的...
CPP17 allows to annotate switch case fall through using the [[fallthrough]] attribute instead of a raw comment. On newer compilers this cause redundant warnings when compiling with the -Wimplicit-fallthrough diagnostic flag. Example for ...
fallthroughcase'b': fmt.Println("The integer was <= 5") fallthroughcase'c': fmt.Println("The integer was <= 6")default: fmt.Println("default case") } 输出: default case 总结:switch分支中使用变量进行判断的时,fallthrough正确的分支开始其作用。
The switch fallthrough has been widely considered a design defect in C, a misfeature or, to use Marshall Cline's definition, evil [1]. An overwhelming majority of the time the fallthrough to the next case is not appropriate, and it's easy to forget to "break" at the end of a case...
有错误提示,显示:cannot fallthrough final case in switch fallthrough不能用在switch的最后一个分支。 示例程序2: 上述示例是true、false常量进行分支判断,看如下变量示例。 s := "abcd" switch s[1] { case 'a': fmt.Println("The integer was <= 4") ...
case IRP_MJ_DEVICE_CONTROL: case IRP_MJ_INTERNAL_DEVICE_CONTROL: // || || Fall through || || // \/ \/ \/ \/ default: return NULL; } While the banner is certainly human readable, it is not apparent to static analysis tools that the fall through was intentional. Today I discovered...
switch case order and fallthrough.Fixes#221and#661(#662) bb292a4 gmp216added a commit to gmp216/c2go that referenced this issueApr 6, 2018 switch case order and fallthrough.Fixeselliotchance#221andelliotc… 3f6368b elliotchanceadded a commit that referenced this issueApr 7, 2018 ...
fall through To fail; miscarry:Our plans fell through at the last minute. fall to To begin an activity energetically:"The press fell to with a will"(Russell Baker). Idioms: fall backon/upon 1.To rely on:fall back on old friends in time of need. ...
I'm confused as to how fallthrough is limited in switch. For example the following works: string switch_test = "a"; switch (switch_test) { case "a": case "b": case "c": doSomething(a); break; } but the following does not work: string switch_test = "a"; switch (switch_test...