sed acting weird

[cppaddict]

Hi,

It would be a great help if anyone could explain this:

echo aaabbbccc | sed 's/[^a]//g'

is producing "bbbccc"

echo aaabbbccc | sed 's/[a]//g'

is also producing "bbbccc"

Shouldn't the first example produce "aaa"?

Am I using [^ ] incorrectly?

Thanks for any help,
cpp