Perl初级教程 - 第三天 | |
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第一页:条件语句 Perl当然也支持if/then/else语句,下面是一个例子: if ($a) { print "The string is not empty\n"; } else { print "The string is empty\n"; } 记住,空字符串被认为是false,如果$a是字符串"0",结果将是"empty"。 条件语句中也可以使用elsif: if (!$a) # The ! is the not operator { print "The string is empty\n"; } elsif (length($a) == 1) # If above fails, try this { print "The string has one character\n"; } elsif (length($a) == 2) # If that fails, try this { print "The string has two characters\n"; } else # Now, everything has failed { print "The string has lots of characters\n"; } 注意:elsif中确实缺一个"e"。>> Perl初级教程
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