小编San*_*rix的帖子

my $test = "There was once an\n ugly ducking";
if ($test =~ m/ugly/g) {
    if ($test =~ m/here/g) {
        print 'Match';
    }
}

结果没有输出,但是

my $test = "There was once an\n ugly ducking";
if ($test =~ m/here/g) {
    if ($test =~ m/ugly/g) {
        print 'Match';
    }
}

比赛结果!

如果我从正则表达式中删除g标志,那么第二次内部测试会匹配在$ test中出现的匹配项.我找不到为什么会这样的参考.