PHP删除所有空格后的特定字符

Question

我有一个文本文件，它看起来是这样的：

What word is on page 9, 4 words from the left on line 15? account 
What word is on page 11, 2 words from the left on line 5? always 

有没有一种方法，我可以后删除所有空间的“？”所以它看起来是这样的（空间量在整个实际的文本文件中的所有不同）：

What word is on page 9, 4 words from the left on line 15?account 
What word is on page 11, 2 words from the left on line 5?always 

Answer 1

使用正则表达式：

$str = 'What word is on page 9, 4 words from the left on line 15? account'; 
echo preg_replace('/\?\s+/', '?', $str); 

Answer 2

$input = 'What word is on page 9, 4 words from the left on line 15? account'; 
echo preg_replace('/\?\s+/', '?', $input); 

See it in action