JavaScript String indexOf() Method
Example
Search a string for "welcome":
var str = "Hello world, welcome to the universe.";
var n = str.indexOf("welcome");
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More "Try it Yourself" examples below.
Definition and Usage
The indexOf() method returns the position of the first occurrence of a specified value in a string.
This method returns -1 if the value to search for never occurs.
Note: The indexOf() method is case sensitive.
Tip: Also look at the lastIndexOf() method.
Browser Support
| Method | |||||
|---|---|---|---|---|---|
| indexOf() | Yes | Yes | Yes | Yes | Yes |
Syntax
string.indexOf(searchvalue, start)
Parameter Values
| Parameter | Description |
|---|---|
| searchvalue | Required. The string to search for |
| start | Optional. Default 0. At which position to start the search |
Technical Details
| Return Value: | A Number, representing the position where the specified searchvalue occurs for the first time, or -1 if it never occurs |
|---|---|
| JavaScript Version: | ECMAScript 1 |
More Examples
Example
Find the first occurrence of the letter "e" in a string:
var str = "Hello world, welcome to the universe.";
var n = str.indexOf("e");
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Example
Find the first occurrence of the letter "e" in a string, starting the search at position 5:
var str = "Hello world, welcome to the universe.";
var n = str.indexOf("e", 5);
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