^a-zA-Z0-9 excluding spaces?

You could also try with:

/[^a-zA-Z0-9\s]/gi

try ^[\d\w]*$ or ^[\w]*$ as reg' Expression means from ^(start) to $(end) match 0-9a-zA-Z only

for c++ ansistring="^[\\d\\w]*$";

If you only want to exclude spaces use:

[^ ]*

Test the regex here if you want.