I am url encoding a string of text to pass along to a function. However, it encodes the second space in a double-space as "%A0". This means that when I decode the string, the "%A0" is displayed as a question mark in a black box.
I really just need to be able to remove the extra space, but I'd like to understand what is causing this and how to handle it correctly.
For example:
Something Something else
Encodes to:
Something+%A0Something+else
%A0 indicates a NBSP (U+00A0). + indicates a normal space (U+0020). The NBSP displays as a replacement character (U+FFFD) because the encoding of the character does not match the encoding of the page, so its byte sequence is not valid for the page.
A quick Googling shows that %A0 is the non-breaking space character or in html. A + is the form-encoding for a standard space character.
The problem you're having is that the second "space" is not really a space, it's a character that that font doesn't have a glyph (I think that's the term) to represent (hence the black box with the question mark). %A0 is the escape code for that character. Your code is technically handling it correctly, I think the problem is with whatever is generating the string in the first place.
If I refer to the chart on this page, %A0 is not a space. %20 is the space caracter's encoded value.
来源：https://stackoverflow.com/questions/6192788/difference-between-and-a0-urlencoding