JavaScript String lastIndexOf() method

The JavaScript string lastIndexOf() method is used to search the position of a particular character or string in a sequence of given char values. It behaves similar to indexOf() method with a difference that it start searching an element from the last position of the string.

The lastIndexOf() method is case-sensitive. The index position of first character in a string is always starts with zero. If an element is not present in a string, it returns -1.

Syntax

These are the following ways used to search the position of an element.

Parameters

ch - It represent the single character to search like 'a'.

index - It represent the index position from where search starts.

str - It represent the string to search like "Java".

JavaScript String lastIndexOf() method example

Let's see the various ways of searching the position of an element with help of simple examples.

Example 1

Here, we will print the position of a single character.

Output:

23

Example 2

In this example, we will provide the index value from where the search starts.

Output:

21

Example 3

Here, we will print the position of a first character of string.

Output:

20

Example 4

In this example, we will provide the index value from where the search starts.

Output:

6

Example 5

Here, we will try to search the element by changing its case-sensitivity.

Output:

-1