Property/method

Description

global

Read-only true if the g modifier was set when creating the regexp object.

ignoreCase

Read-only. true if the i modifier was set when creating the regexp object.

multiline

Read-only. true if the m modifier was set when creating the regexp object

lastIndex

Contains the position in the string where the next match should start. test() and exec()set this position after a successful match. Only relevant when the g (global) modifier was used:

    > var re = /[dn]o+dle/g;   
    > re.lastIndex;   
    0   
    > re.exec("noodle doodle");   
    ["noodle"]   
    > re.lastIndex;   
    6   
    > re.exec("noodle doodle");   
    ["doodle"]   
    > re.lastIndex;   
    13   
    > re.exec("noodle doodle");   
    null   
    > re.lastIndex;   
    0   

source

Read-only. Returns the regular expression pattern (without the modifiers):

    > var re = /[nd]o+dle/gmi;   
    > re.source;   
    "[nd]o+dle"   

exec(string)

Matches the input string with the regular expression. On a successful match returns an array containing the match and any capturing groups. With the g modifier, it matches the first occurrence and sets the lastIndex property. Returns null when there's no match:

    > var re = /([dn])(o+)dle/g;   
    > re.exec("noodle doodle");   
    ["noodle", "n",   "oo"]   
    > re.exec("noodle doodle");   
    ["doodle", "d",   "oo"]   

The arrays returned by exec() have two additional properties: index (of the match) and input (the input string being searched).

test(string)

Same as exec() but only returns true or false:

    > /noo/.test('Noodle');   
    false   
    > /noo/i.test('Noodle');   
    true