What does this ~ operator mean here?

Question

Example:

set_error_handler(array($this, \'handleError\'), E_ALL & ~E_STRICT & ~E_WARNING & ~E_NOTICE);

what does that suppose t

Answer 1

See Bitwise Operators : it's the "not" operator (quoting) :

~ $a
Bits that are set in $a are not set, and vice versa.

Which means, taking an example inspired from what you posted, that this portion of code :

var_dump(decbin(E_STRICT));
var_dump(decbin(~E_STRICT));

Will get you this output :

string '100000000000' (length=12)
string '11111111111111111111011111111111' (length=32)

(Add a couple of 0 for padding on the left of the first line, and you'll see what I mean)

Removing the padding from the second output, you get :

100000000000
011111111111

Which means the ~ operator gave a 0 bit for each bit that was equal to 1 in the intput -- and vice-versa,