Counting regex pattern matches in one line using sed or grep?

Question

I want to count the number of matches there is on one single line (or all lines as there always will be only one line).

I want to count not just one match per line as in

Answer 1

Maybe below:

echo "123 123 123" | sed "s/123 /123\n/g" | wc -l

( maybe ugly, but my bash fu is not that great )