# lastIndexOf method

The `lastIndexOf` method searches for the last occurrence of a substring in a string. In this case, it is necessary to pay attention to the character case specified in the first parameter. The search is performed from the end of the string. The method will return the position of the first match from the end, and if it is not found, it will return `-1`. As the second optional parameter, you can pass the character number from where the search should start.

## Syntax

`string.lastIndexOf(what to search, [where to start search]);`

## Example

Let's find the position of the last occurrence of a substring:

`let str = 'ab cd cd cd ef'; let res = str.lastIndexOf('cd'); console.log(res);`

The code execution result:

`9`

## Example

Let's set the search start position:

`let str = 'ab cd cd cd ef'; let res = str.lastIndexOf('cd', 8); console.log(res);`

The code execution result:

`6`

## See also

- the `startsWith` method
  that checks the start of a string
- the `endsWith` method
  that checks the end of a string
- the `indexOf` method
  that searches for the first occurrence of a substring
- the `includes` method
  that searches for a string
- the `at` method
  that searches for a string character

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