JavaScript String indexOf() method

The JavaScript string indexOf() method is used to search the position of a particular character or string in a sequence of given char values. This 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 methods 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".

Return

Index of a particular character.

JavaScript String indexOf() 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:

2

Example 2

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

Output:

7

Example 3

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

Output:

6

Example 4

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

Output:

20

Example 5

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

Output:

-1