[Solved] Looping var from two files

Hey Guys,

I have been searching but unable to find solution for this;
Got 2 files:

#File A
A
B
C

#File B
1
2
3

And would like to 'merge' file and get a out put like;

A1
A2
A3
B1
B2
B3
C1
C2
C3

Would anyone have a suggest to do above ?
SH , Bash - no problem, I can do most env.

Thanks in advance for any suggestions

while read a;do while read b;do echo $a$b;done < file_b;done < file_a

Worked like a charm.
Thank you, danmero very much for taking the time to help me solve the problem.