C# Quantifiers in Regular Expression

Quantifiers in C# specify how many instances of the previous element (which can be a character, a group, or a character class) must be present in the input string for a match to occur.

Quantifier Description Pattern Matches
* Matches the previous element zero or more times. \d*\.\d ".0", "19.9", "219.9"
+ Matches the previous element one or more times. "be+" "bee" in "been", "be" in "bent"
? Matches the previous element zero or one time. "rai?n" "ran", "rain"
{ n } Matches the previous element exactly n times. ",\d{3}" ",043" in "1,043.6", ",876", ",543", and ",210" in "9,876,543,210"
{ n ,} Matches the previous element at least n times. "\d{2,}" "166", "29", "1930"
{ n , m } Matches the previous element at least n times, but no more than m times. "\d{3,5}" "166", "17668" "19302" in "193024"
*? Matches the previous element zero or more times, but as few times as possible. \d*?\.\d ".0", "19.9", "219.9"
*? Matches the previous element zero or more times, but as few times as possible. \d*?\.\d ".0", "19.9", "219.9"
+? Matches the previous element one or more times, but as few times as possible. "be+?" "be" in "been", "be" in "bent"
?? Matches the previous element zero or one time, but as few times as possible. "rai??n" "ran", "rain"
{ n }? Matches the preceding element exactly n times. ",\d{3}?" ",043" in "1,043.6", ",876", ",543", and ",210" in "9,876,543,210"
{ n ,}? Matches the previous element at least n times, but as few times as possible. "\d{2,}?" "166", "29", "1930"
{ n , m }? Matches the previous element between n and m times, but as few times as possible. "\d{3,5}?" "166", "17668" "193", "024" in "193024"
Updated on: 2019-07-30T22:30:23+05:30

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