my $variable = "world"; my $string = "Hello, Perl!"; $string =~ s/Perl/$variable/; print $string; 在这个示例中,我们将$variable的值设置为"world",并将$string的值设置为"Hello, Perl!"。然后,我们使用s/Perl/$variable/运算符将"Perl"替换为$variable的值,即"world"。最后,我们打印出替换...
我建議你最好在每個副程式前面加上對這段副程式的描述,特別是需要傳遞的參數要註明清楚。 (d) Variable Localization:my or local通常我們在程式中定義的變數都是全域變數,所以在副程式中若要把變數區域化則要加上 my 或 local 關鍵字,例如:my $x=3;,若副程式所用的變數名不小心和主程相同,Perl會以目前正在...
Perl是 Practical Extraction and Report Language 的缩写”实用报表提取语言”是一种功能强大功能丰富的脚本编程语言,最初的设计者为拉里·沃尔(Larry Wall)诞生于20世纪80年代末期并由他不断更新和维护的编程语言。 其思想借用了C、sed、awk、shell脚本以及很多其他编程语言的特性,所以它的文本处理能力是及其强大的是...
ge Returns True if the operand on the left is stringwise greater than or equal to the operand on the right of the operator. Returns False otherwise. gt Returns True if the operand on the left is stringwise greater than the operand on the right of the operator. Returns False otherwise. c...
eval STRING Any errors are returned in the @a variable. index This function returns the position of the first occurance of the specified SEARCH string. If POSITION is specified, the occurance at or after the position is returned. The value -1 is returned if the SEARCH string is not found....
Search and replace or tr If we have a string which needs to be modified, while a regex will almost always be much more flexible,"tr", an oft underused tool, can still be a useful. One scenario might be replace all vowels with another character. The regex solution might look like this...
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)
$_ the default variable of Perl Perl split - to cut up a string into pieces The diamond operator <> of Perl $_[0] Constructor and accessors in classic Perl OOP Subroutines and functions in Perl $` $` $a $a $a - $b - Special variables when using sort(). Don't ...
Assign a value (string literal) to the variable. $mystring = "Hello world!"; Does the string contains the word "World"? if($mystring =~ m/World/) { print "Yes"; } No, it doesn't. The binding operator=~with the match operatorm//does a pattern search on$mystringand returns true...
Running Perl programs Safety net Basic syntax overview Perl variable types Scalars, Arrays, Hashes Variable scoping Conditional and looping constructs if, while, for, foreach Builtin operators and functions Arithmetic, Numeric comparison, String comparison, Boolean logic, Miscellaneous Files and I/O ...