JavaScript String indexOf() Method
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JavaScript String indexOf() Method
The indexOf() method returns the position of the first occurrence of a specified value in a string.
Note: This method is case sensitive.
Example
HTML Online Editor
<!DOCTYPE html>
<html>
<body>
<script>
var str = "Hello there my old friend"
var result = str.indexOf("fri");
document.write(result);
</script>
</body>
</html>
Syntax
str.indexOf(searchString, startFrom)
Parameter Values
| Value | Type | Explanation |
|---|---|---|
| searchString | Required | Specifies the characters to be searched for within this string. |
| startFrom | optional | Specifies the starting position of a string (str). If omitted, the default value is '0'. |
Return Value
| Value | Condition |
|---|---|
| -1 | When the searched value are not found within this string. |
| 0 to str.length | A index of a search value within this string. |
indexOf() with Specified Starting Position
Example
HTML Online Editor
<!DOCTYPE html>
<html>
<body>
<script>
var str = "Hello there my old friend"
var result = str.indexOf("Hello", 10);
// str = e my old friend;
document.write(result);
</script>
</body>
</html>
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