namespace bakbaba;
function bab(){
echo "bi";
}
namespace kkk;
function k1(){
echo "k1";
}
bakbababab();//Use another namespace under the KKK namespace, note the in front
use bakbaba as b;//It is still in the KKK namespace, but the following method is correct when using an alias
#use bakbaba as b;//You may not use the sign in front
bbab();//There should be no sign before using the namespace under the alias
k1();//There is no error in calling this function, indicating that use does not affect the current namespace