(8)设串S1="I AM",S2="A SDUDENT",则ConcatStr(S1,S2)=
(8)设串S1="I AM",S2="A SDUDENT",则ConcatStr(S1,S2)=
1
(8)设串S1="I AM",S2="A SDUDENT",则ConcatStr(S1,S2)=