Add Searching Tools with Regular Expression Operators in JavaScript
The regular expression mechanism adds extremely powerful searching tools to your programming. Here are some of the most commonly used regular expressions as they are used in JavaScript.
| Operator and Description |
Sample pattern |
Matches and Doesn‘t match |
| . (period)
Any single |
. | E
n |
| ^ Beginning of string | ^a | apple
Banana |
| $ End of string | a$ | banana
Apple |
| [characters]
Any of a list of characters in braces |
[abcABC] | A
D |
| [char range]
Any character in the range |
[a-zA-Z] | F
9 |
| d
Any single numerical digit |
ddd-dddd | 123-4567
The-thing |
| b A word boundary | btheb | the
Theater |
| +
One or more occurrences of the previous character |
d+ | 1234
Text |
| *
Zero or more occurrences of the previous character |
[a-zA-Z]d* | B17, g
7 |
| {digit}
Repeat preceding character digit times |
d{3}-d{4} | 123-4567
999-99-9999 |
| {min, max}
Repeat preceding character at least min but not more than max times |
.{2,4} | Ca, com, info
watermelon |
| (pattern segment)
Store results in pattern memory returned with code |
^(.).*1$ | gig, wallow
Bobby |