exec(str)

match(regex) to return multiple occurrences with a single function execution.

Execute the search for a regular expression match in a string and return the first matched sub-string. This function is an implementation of the standard JavaScript RegExp exec() method. The return value is an array with the following elements and properties:

Index 0: The matched sub-string
Index 1-n: Matches for parenthesized sub-strings, if any
index: The starting index in the string where the match was found
input: The original string

The RegExp object (i.e., the regular expression pattern) has the following properties:

lastIndex: For global search (using “g” flag), the index from which to begin the next search (i.e., conclusion of previous match), otherwise 0.
ignoreCase: true if i flag was set, otherwise false
global: true if g flag was set, otherwise false
multiline: true if m flag was set, otherwise, false
source: The specified regular expression

If the global g flag is used, the exec() method updates the RegExp object so that the subsequent calls to the exec() method find additional occurrences of the pattern within the string.

Example

Search for any numbers using the regex /[0-9]+/g.

var pattern = /[0-9]+/g;
var str = 'Joe Miller, 123-45-6789, age 79, was billed $4357 on April 2, 2017.'
var result = pattern.exec(str);

result[0] // returns 123
result.index // returns 12
result.input // returns 'Joe Miller, 123-45-6789, age 79, was billed $4357 on April 2, 2017.'
pattern.lastIndex; // returns 15.0
pattern.global; // returns true
pattern.source; // returns [0-9]+

If the method is executed a second time, the global search continues in the string.

var result = pattern.exec(str);

result[0] // returns 45
result.index // returns 16
result.input // returns 'Joe Miller, 123-45-6789, age 79, was billed $4357 on April 2, 2017.'
pattern.lastIndex; // returns 18.0
pattern.global; // returns true
pattern.source; // returns [0-9]+