* Specifies zero or more matches. Same as {0,}.
+ Specifies one or more matches. Same as {1,}.
? Specifies zero or one matches. Same as {0,1}.
{n} Specifies exactly n matches.
{n,} Specifies at least n matches.
{n,m} Specifies at least n, but no more than m, matches.
*? Specifies the first match that consumes as few repeats as possible (lazy *).
+? Specifies as few repeats as possible, but at least one (lazy +).
?? Specifies zero repeats if possible, or one (lazy ?).
{n}? Equivalent to {n} (lazy {n}).
{n,}? Specifies as few repeats as possible, but at least n (lazy {n,}).
{n,m}? Specifies as few repeats as possible between n and m (lazy {n,m}).
*lazy quantifier: If ? is used immediately after any of the quantifiers *, +, ?, or {}, it makes the quantifier non-greedy (matching the minimum number of times), as opposed to the default, which is greedy (matching the maximum number of times).
var re = /a{1,3}(\w)/ ; var ary = re.exec('aaab'); window.alert(ary[1]); => "b"
var re = /a{1,3}?(\w)/; var ary = re.exec('aaab'); window.alert(ary[1]); => "a"
