I am doing integer comparison in bash (trying to see if the user is running as root), and I found two different ways of doing it:

Double equals:

if [ $UID == 0]
then
fi

-eq

if [ $UID -eq 0]
then
fi

I understand that there's no >= or <= in bash, only -ge and -le, so why is there a == if there's a -eq?

Is there a difference in the way it compares both sides?

I am doing integer comparison in bash (trying to see if the user is running as root), and I found two different ways of doing it:

Double equals:

if [ $UID == 0 ]
then
fi

-eq

if [ $UID -eq 0 ]
then
fi

I understand that there's no >= or <= in bash, only -ge and -le, so why is there a == if there's a -eq?

Is there a difference in the way it compares both sides?