Difference between ".+" and ".+?"

Question

Can someone please explain the difference between .+ and .+?

I have the string: "extend cup end table"

1. The pattern e.+d finds: extend cup end
2. The pattern e.+?d finds: extend and end

I know that + is one or more and ? is one or zero. But I am not able to understand how does it work.

Answer 1

Both will match any sequence of one or more characters. The difference is that:

• .+ is greedy and consumes as many characters as it can.
• .+? is reluctant and consumes as few characters as it can.

See Differences Among Greedy, Reluctant, and Possessive Quantifiers in the Java tutorial.

Thus:

• e.+d finds the longest substring that starts with e and ends with d (and contains at least one character in between). In your example extend cup end will be found.
• e.+?d find the shortest such substring. In your example, extend and end are two such non-overlapping matches, so it finds both.