# !/usr/bin/perl
$a = "aaaaaaab";
if ($a =~ m/a?/)
{
print"Yes!!!! ---- $a\n";
}else{
print"NOOOO!!! ------- $a\n";
}
print"<-------------------\n";
输出为
Yes!!!! ---- aaaaaaab
<-------------------
# !/usr/bin/perl
$a = "aaabrcdbr";
if ($a =~ m/a?/)
{
print"Yes!!!! ---- $a\n";
}else{
print"NOOOO!!! ------- $a\n";
}
print"<-------------------\n";
这个的输出是Yes!!!。怎么解释呀?