Front HTML space and background PHP utf-8 space

An issue was found today when working with the HTML input box:

In the User name input box, enter admin "' p (in the middle is a space), point to save the background prompt data saved successfully, supposedly not modified, through the Chrome debugging tool found to the background data is like this:

data_mark=&user=admin%c2%a0%'p&ip=1.2.3.4&pwd=&status=0 &edit_type=edit

That is, the browser to the space to the "%c2%a0", the database and the foreground display are normal and have a space, but take out the comparison, they are completely unequal , through the search learned:

Front-end Space:   ;  &#xA0 to the background is UTF-8 spaces: C2 A0 ASCII 194 + 160

So in the background to get Urser data after the space conversion, you can normally save data

$data ['user'] = Str_replace (Chr (194). chr // utf-8 Spaces

Reference:

Https://en.wikipedia.org/wiki/Non-breaking_space

Https://www.cnblogs.com/oldphper/p/4128138.html

Front HTML space and background PHP utf-8 space