正则表达式-如果结尾字符为“-”，则不匹配

Question

I have a regex as below

^Schedule\s?(A|B|C|D|E|F|H|J|K|L|M|R|SE)?

so this will match anything like " Schedule A i need help".

I want restriction for the character "-" ie it should not give a match if the string is like "Schedule A - i need help" .

But it should give a match if Schedule A is followed by anything other than a space and "-".

Answer 1

Negative look aheads will be helpful here

^Schedule\s*([ABCDEFHJKLMR]|SE)(?!\s+-)

• (?!\\s+-) Negative look ahead, checks if the matches string is not followed by space ( \\s+ ) and the - .

• Note The optional quantifiers ? are not required as it causes the regex engine to skip them.

• [ABCDEFHJKLMR] Character class, matches a single character from this set .

Regex Demo