为什么两个字符串看起来相同，但它们不是？

Question

我的PHP代码：

$hello = "Hello, world! "; 
echo $string1 = sprintf("%'#-20s\n", $hello); // Displays "Hello, world! ######" 
echo $string2 = str_pad($hello, 20, "#");  // Displays "Hello, world! ######" 
echo ($string1 == $string2) ? "Indeed they're equal" : "They're not equal"; 
               // Displays "They're not equal" 
echo strcmp($string1, $string2); // Displays "-1", which (according to PHP Manual) 
           // means that $string1 is less than $string2 

有什么理由琴弦$string1 & $string2不相等？

Answer 1

因为在第一个sprintf中有一个新行\n。