一个子程序的返回值问题~

xp1842

eg1:
sub myprog1{
    my $sum;
    for(1..9){
        ++$sum;
    }
    $sum;
}

print myprog1;

res:  9

sub myprog2{
    my $sum;
    for(1..9){
        ++$sum;
    }
}

print myprog2;
res: ''(啥都不打印)
按照learning perl 所说如果不加return显式返回值，则返回子程序最后一个表达式的返回值。
第一个是ok的啦。第二个是因为最后运行是for(){}中的‘}’字符（如果它算表达式的话）才不能正确返回么？


初学~别鄙视

rubyish

1. If no return is found and if the last statement is an expression, its value is returned. If the last statement is a loop control structure like a foreach or a while , the returned value is unspecified. The empty sub returns the empty list.

复制代码

http://perldoc.perl.org/perlsub.html

xp1842

回复 2# rubyish


    谢谢，晓得啦。:wink: