看来的代码，测试通过

#!/usr/bin/perlsub func1 {    print "func1 is running\n";}sub func_test {    my $func_ref = shift;    # ref will return 'CODE' if it's function reference    if ( ( ref($func_ref) eq "CODE" )        && defined( &{
   $func_ref} ) )    {        &{
   $func_ref};        print $@ if $@;    }    else {        print "Not real function was called! \n";    }}## testing from heremy $func_ref = \&func1;my $anoy_ref = sub { print "anonymous function is running\n" };my $var      = "abcd";my $var_ref  = \$var;func_test($func_ref);func_test($anoy_ref);func_test($var);func_test($var_ref)

my $variableName = 10 #定义私有变量

function test{    my $a = shift;}#函数参数其实是个数组#shift删除并返回数组第一个元素

 修改之前的代码：

#! /usr/bin/perl#传参测试sub hello{    my $a = shift;    print $a;}&hello("hello,world\n");#返回值测试sub max{    my $a = shift;    my $b = shift;    if ($a > $b)    {        return $a;    }    else    {        return $b;    }}$n = &max(10,23);print $n;print "\n";