Regular Expression Basic
| Syntax | Description |
|---|---|
abc… |
Letters |
123… |
Digits |
\d |
Any Digit |
\D |
Any Non-digit character |
. |
Any Character |
\. |
Period |
[abc] |
Only a, b, or c |
[^abc] |
Not a, b, nor c |
[a-z] |
Characters a to z |
[0-9] |
Numbers 0 to 9 |
\w |
Any Alphanumeric character |
\W |
Any Non-alphanumeric character |
{m} |
m Repetitions |
{m,n} |
m to n Repetitions |
* |
Zero or more repetitions |
+ |
One or more repetitions |
? |
Optional character |
\s |
Any Whitespace |
\S |
Any Non-whitespace character |
^…$ |
Starts and ends |
(…) |
Capture Group |
(a(bc)) |
Capture Sub-group |
(.*) |
Capture all |
(abc|def) |
Matches abc or def |
Some Common Regular Expressions
| Description | Regular Expression |
|---|---|
| Canada Postal Code | [a-zA-Z]\d[a-zA-Z]\s?\d[a-zA-Z]\d |
| US ZIP Code(5 Numbers) | \d{5} |
| URL | [a-zA-z]+:\/\/[^\s]* |
| IP Address | ((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){3}(2[0-4]\d|25[0-5]|[01]?\d\d?) |
| Email Address | \w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)* |
| HTML Tags | <(.*)(.*)>.*<\/\1>|<(.*) \/> |
| Date(yy-mm-dd) | (\d{4}|\d{2})-((1[0-2])|(0?[1-9]))-(([12][0-9])|(3[01])|(0?[1-9])) |
| Time(hh:mm) | ((1|0?)[0-9]|2[0-3]):([0-5][0-9]) |
| Capture tag contents | >([\w\s]*)< |
| Get attribute values | ='([\w://.]*)' |
To Be Continued…
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