perl 判斷整數

http://bbs.chinaunix.net/thread-1596012-1-1.html

使用正規表示式：

$ perl -e 'my $xx=1 ;if ($xx=~/^-?\d+$/){warn "int";}else{warn "not int"};warn $xx'

判斷資料型態(數字、字串、refrence-hash、reference-array)：

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use Scalar::Util qw(looks_like_number);   my $val; $val = { a => "123", b => "456" }; $val = [{ a => "123", b => "456" }]; $val = 6486; $val = "string test"   if(ref($val)){   print ref($val); }else{   print "is", looks_like_number($val) ? '' : ' not', " a number\n"; }

http://stackoverflow.com/questions/1731333/how-do-i-tell-what-type-of-value-is-in-a-perl-variable
使用ref()
http://stackoverflow.com/questions/12647/how-do-i-tell-if-a-variable-has-a-numeric-value-in-perl
使用 use Scalar::Util qw(looks_like_number);