Just wanted to share this little collection of “Most Wanted Regular Expressions”
Regular expression examples for decimals input
Positive Integers — ^d+$
Negative Integers — ^-d+$
Integer — ^-{0,1}d+$
Positive Number — ^d*.{0,1}d+$
Negative Number — ^-d*.{0,1}d+$
Positive Number or Negative Number – ^-{0,1}d*.{0,1}d+$
Phone number — ^+?[ds]{3,}$
Phone with code — ^+?[ds]+(?[ds]{10,}$
Year 1900-2099 — ^(19|20)[d]{2,2}$
Date (dd mm yyyy, d/m/yyyy, etc.) — ^([1-9]|0[1-9]|[12][1-9]|3[01])D([1-9]|0[1-9]|1[012])D(19[0-9][0-9]|20[0-9][0-9])$
IP v4 — ^(d|[1-9]d|1dd|2[0-4]d|25[0-5]).(d|[1-9]d|1dd|2[0-4]d|25[0-5]){3}$
Regular expression examples for Alphabetic input
Personal Name — ^[w.’]{2,}([s][w.’]{2,})+$
Username — ^[wd_.]{4,}$
Password at least 6 symbols — ^.{6,}$
Password or empty input — ^.{6,}$|^$
email — ^[_]*([a-z0-9]+(.|_*)?)+@([a-z][a-z0-9-]+(.|-*.))+[a-z]{2,6}$
domain — ^([a-z][a-z0-9-]+(.|-*.))+[a-z]{2,6}$
Url — http://([w-]+.)+[w-]+(/[w- ./?%&=]*)?
Other regular expressions
Match no input — ^$
Match blank input — ^s[t]*$
Match New line — [rn]|$