Delete spaces php

Delete spaces php

I need delete all tags from string and make it without spaces.
I have string
"<span class="left_corner"> </span><span class="text">Adv</span><span
class="right_corner"> </span>"
After using strip_tags I get string
" Adv "
Using trim function I can`t delete spaces.
JSON string looks like "\u00a0...\u00a0".
Help me please delete this spaces.