#!/usr/bin/perl

sub 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 here
my $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

#! /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";