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Break out of a loop The “last” keyword is the equivalent of “break” in C. It will exit out of a loop. It is also more powerful than “break”, as it can exit out of an outermost loop. For example: LOOP_OUTER: for ($i=0;$i<10;++i) { for ($j=0;$j<10;++i) { if...
Thisisthe syntaxforhere documentandit willcontinueuntilit encounters a EOFinthe first line. Thisiscaseofdoublequote so variable value will be interpolated.Forexample valueofa =10Thisiscaseofsinglequote so variable value will be interpolated.Forexample valueofa = $a1234567 逃脱角色 Perl使用反斜杠(\...
3、类C的for循环 ,如 for ($count=1; $count <= 5; $count++) { # statements inside the loop go here } 下面是在for循环中使用逗号操作符的例子: for ($line = <STDIN>, $count = 1; $count <= 3; $line = <STDIN>, $count++) { print ($line); } 它等价于下列语句: $line = <S...
无法准确地告诉您超时代码应该放在哪里，但是您应该能够使用Time::Out轻松地完成您想要的任务。就用 ...
Perl 诊断消息 类别含义 (W)警告(可选) (D)反对(可选) (S)严重警告(必需) (F)致命错误(可捕获) (P)你应该从未见过的内部错误(恐慌性的)(可捕获) (X)非常致命的错误(不可捕获) (A)外来错误消息(不是Perl生成的)
foreach $temp (@list) { if ($temp == 2) { $temp = 20; } } 此时@list已变成了(1, 20, 3, 4, 5)。 5、do循环 do { statement_block } while_or_until (condexpr); do循环至少执行一次循环。 6、循环控制 退出循环为last,与C中的break作用相同;执行下一个循环为next,与C中的continue作用...
词法范围通常是一个带有一组括号的代码块,例如定义子例程主体的那些或标记if, while, for, foreach,和eval语句的代码块的代码块。 以下是一个示例,说明如何使用my运算符定义单个或多个私有变量 - sub somefunc { my $variable; # $variable is invisible outside somefunc() my ($another, @an_array, %...
Throughout this document I'm using exampleprintstatements to output data but not explicitly appending line breaks. This is done to prevent me from going crazy and to give greater attention to the actual string being printed in each case, which is invariably more important. In many examples, th...
break Break out of a "given()" block. This keyword is enabled by the "switch" feature: see feature for more information. caller EXPR caller Returns the context of the current subroutine call. In scalar context, returns the caller's package name if there is a caller (that is, if we'...