JS String Prototype Match - thelastmile/FreeCodeCamp GitHub Wiki
JavaScript String prototype match
The match()
method retrieves the matches when matching a string against a regular expression.
Syntax
str.match(regexp)
Parameters
regexp
A regular expression object. If a non-RegExp object obj is passed, it is implicitly converted to a RegExp by using new RegExp(obj)
.
Returns
An Array
containing the matched results or null
if there were no matches.
Description
If the regular expression does not include the g
flag, returns the same result as RegExp.exec()
. The returned Array
has an extra input property, which contains the original string that was parsed. In addition, it has an index property, which represents the zero-based index of the match in the string.
If the regular expression includes the g
flag, the method returns an Array
containing all matched substrings rather than match objects. Captured groups are not returned. If there were no matches, the method returns null
.
Examples
var str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
var regexp = /[A-E]/gi;
var matches_array = str.match(regexp);
console.log(matches_array);
// ['A', 'B', 'C', 'D', 'E', 'a', 'b', 'c', 'd', 'e']
var str = 'For more information, see Chapter 3.4.5.1';
var re = /(chapter \d+(\.\d)*)/i;
var found = str.match(re);
console.log(found);
// logs ['Chapter 3.4.5.1', 'Chapter 3.4.5.1', '.1']
// 'Chapter 3.4.5.1' is the first match and the first value
// remembered from `(Chapter \d+(\.\d)*)`.
// '.1' is the last value remembered from `(\.\d)`.