为什么sprintf()不输出任何内容? [英] Why doesn't sprintf() output anything?

问题描述

我以前从未使用过这些功能，但是在阅读了很多有关sprintf()的内容之后，我决定应该了解它.

I've never used these functions before but after reading a lot about sprintf(), I decided I should get to know it.

所以我继续进行以下操作.

So I went ahead and did the following.

function currentDateTime() {
  list($micro, $Unixtime) = explode(" ",microtime());
  $sec= $micro + date("s", $Unixtime);
  $sec = mb_ereg_replace(sprintf('%d', $sec), "", ($micro + date("s", $Unixtime)));
  return date("Y-m-d H:i:s", $Unixtime).$sec;
}

sprintf(currentDateTime());

它不打印任何内容.另一方面，使用printf()函数:

It prints nothing. Using the printf() function on the other hand:

printf(currentDateTime());

它可以很好地打印结果.那么这两个函数有什么区别?我该如何正确使用sprintf()函数?

It prints the result just fine. So what's the difference between these 2 functions and how do I properly use the sprintf() function?

推荐答案

sprintf()返回一个字符串，printf()显示它.

sprintf() returns a string, printf() displays it.

以下两个相等:

printf(currentDateTime());
print sprintf(currentDateTime());

这篇关于为什么sprintf()不输出任何内容?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！