String.indexOf
indexOf($matchString, $options={}) -> number
Description
Find the index position of $matchString.
If the substring does not exist, it will return 0.
Note: To simply check if the substring exists, see contains().
'abc xyz'.indexOf('abc')
//= 1
'abc xyz'.indexOf('xyz')
//= 5
'abc xyz'.indexOf('jkl')
//= 0
Options
| Option | Value | Description |
|---|---|---|
ignoreCase |
true/false | Match upper and lowercase versions of each character. |
startIndex |
number | Start at index position (default: 1) |
'abc xyz'.indexOf('XYZ', -ignoreCase)
//= 5
'abc xyz'.indexOf('XYZ', { ignoreCase, startIndex: 3 })
//= 5
Regex Patterns
The $matchString argument can also be a Regex.
// \d+ = one or more consecutive digits 'ABC 123'.indexOf(rx'\d+') //= 5 // i = ignore case 'abc def XYZ'.indexOf(rx'xyz'i) //= 9