爲什麼打印命令在STDIN之後執行，雖然之前被調用過？

Question

我有一個簡單的程序

use strict; 
use warnings; 

print "Enter a number:\n"; 
my $number1 = <STDIN>; 
chomp $number1; 
print "Enter another number:\n"; 
my $number2 = <STDIN>; 
chomp $number2; 
if ($number2 == 0) { 
    print "error: cnt divide by zero\n"; 
} 
elsif (($number1 == 0) or ($number2 == 1)) { 
    print "$number1\n"; 
} 
else { 
    my $div = $number1/$number2; 
    print "the result is: $div\n"; 
} 

，但我不明白爲什麼打印（輸入號碼，然後輸入另一個號碼STDIN後顯示）。我得到下面的輸出

[612] perl test.pl 
2 
0 
Enter a number: 
Enter another number: 
error:cnt divide by zero 

Answer 1

$| = 1在程序