`X[A-Z]+`

The new expression matches the same set of strings as the previous one, but does not capture the prefix of X characters.

# Reluctant Quantifier

 Regular Expression String Group 0 Group 1 Group 2 Group 3 Group 4

An quantifier in a regular expression may be greedy (the default), reluctant, or possesive. A reluctant quantifier does this:

• Strings are matched from left to right one character at a time.
• A reluctant quantifier matches as few characters as it can without preventing the rest of the regular expression from matching.

An quantifier is made reluctant by appending a question mark. The expression `X+?` matches X one or more times, but matches as few X as it can without preventing other quantifier from matching. For example, when the expression

````(X+?)([A-Z]+)`
```

matches the string

```XXXX
```

the reluctant `X+?` could potentially match the entire string. But it matches as little as possible: the first X . The final `[A-Z]+` of the expression matches the rest the string.

Reluctant quantifier are sometimes called lazy quantifier, because they match as little as possible.

### QUESTION 18:

Here is a string: XXXXX

What parts of the string match the capture group in the following expressions?

• `(X+)[A-Z]+`
• `(X+?)[A-Z]+`