Question: what is the difference between the + and * character in regular expressions?
Answer: 3 Answers. . : which is concatenation like a.b.c would match a text having abc . Some times to indicate concatenation simply two symbols are used back to back. * : match the last symbol 0 or more times, (abc)* would match a null string, abc, abcabc, abcabcabc, but not abcaabc.