Difference between revisions of "Regular Expression"
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(Created page with "RegEx can be tricky! Hopefully this will provide some help. This is an example of perl-regex format which is used in Netbeans and Atom <pre> a-c(\d[{2-2}]\d{1}?[{0-9}]\d) </p...") |
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| − | This will match a-c213 as well as a-c2199 | + | This will match a-c213 as well as a-c2199. It will not match b2199 nor a-c229. Can you figure out why? |
| + | |||
| + | The ? makes the following statement optional. | ||
| + | |||
| + | \d is a digit | ||
| + | |||
| + | [{x-y}] indicates a range from x to y. This can be alphanumeric. | ||
| + | |||
| + | {1} indicates that just that character is accepted. | ||
| + | |||
| + | Everything outside the parentheses is literal. So "a-c" matches that string, literally. | ||
| + | |||
| + | If you perform a search/replace, you can use $1 to grab the first match, $2 for the second, etc. | ||
| + | <pre> | ||
| + | e.g. | ||
| + | input: What is a word | ||
| + | search: What is a(.*) | ||
| + | replace: This is not a$1 | ||
| + | result: This is not a word | ||
| + | </pre> | ||
| + | |||
| + | The (.*) above is a wildcard, it'll match any number of anythings, like the space after "a"! | ||
Latest revision as of 17:13, 25 August 2016
RegEx can be tricky! Hopefully this will provide some help.
This is an example of perl-regex format which is used in Netbeans and Atom
a-c(\d[{2-2}]\d{1}?[{0-9}]\d)
This will match a-c213 as well as a-c2199. It will not match b2199 nor a-c229. Can you figure out why?
The ? makes the following statement optional.
\d is a digit
[{x-y}] indicates a range from x to y. This can be alphanumeric.
{1} indicates that just that character is accepted.
Everything outside the parentheses is literal. So "a-c" matches that string, literally.
If you perform a search/replace, you can use $1 to grab the first match, $2 for the second, etc.
e.g. input: What is a word search: What is a(.*) replace: This is not a$1 result: This is not a word
The (.*) above is a wildcard, it'll match any number of anythings, like the space after "a"!
