how do i copy files from one directory to another directory using a while loop? (like jus say i had a.doc and b.doc in one directory and i want to copy it into another)

i used a if statement but doesn't work

You don't need a while loop. Something like

cp -R dir_a/ dir_b

should work.

cbkihong's example will work to copy entire directorys over. that seems like what you were asking. the -r flag for the cp command tells cp to copy directories recursivley.

coping individual files works the same way, just without the -r flag. eg:
cp file1 somewhere/file1

yeh i did that.....but it keeps having a error that says "too many arguments"

for my if statement i got

if [ -f $HOME/$directory/*.src ]

is there something wrong with that if multiple files are to be copied?

The -f test doesn't accept multiple arguments. *.src is expanded by the shell to all matching filenames, so there are multiple arguments. As being said, from your description you don't even need an "if" to do it. It's as simple as

cp *.src dir_b/

searching for that?:

for x in $HOME/$directory/*.src
do
cp $x $NEWDIR
done

greetings Preßy