how bash word wrap with \ works?

In bash scripts why these lines work:

perl -e "...\
..."

but these don't:

perl -e \
"... \
..."

??

Works fine for me. The only thing i can suggest is, make sure there's nothing between the backslash and the newline. (Any other whitespace could mess things up.)

Make sure there is nothing between the contents of the string and the backslash if spaces are significant (see the second line of your second example).