This is a simple but tricky
Question is Is there different in following two IF Statement comparisons (Note Quotes)
if ($retry_type == 'new')
AND
if ($retry_type == "new")
I know there is difference between
printf("something $var")
AND
printf('something $var')
In your example, there’s no difference.
There is one other difference besides the ability to interpolate variables, though: In a single-quoted string, the only escape sequences that mean anything are
\'and\\. All others are ignored; for example,'\n'actually consists of a backslash and a ‘n’, whereas"\n"is interpreted as a newline.