JavaScript String substring() Method
Example
Extract characters from a string:
var str = "Hello world!";
var res = str.substring(1, 4);
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More "Try it Yourself" examples below.
Definition and Usage
The substring() method extracts the characters from a string, between two specified indices, and returns the new sub string.
This method extracts the characters in a string between "start" and "end", not including "end" itself.
If "start" is greater than "end", this method will swap the two arguments, meaning str.substring(1, 4) == str.substring(4, 1).
If either "start" or "end" is less than 0, it is treated as if it were 0.
Note: The substring() method does not change the original string.
Browser Support
| Method | |||||
|---|---|---|---|---|---|
| substring() | Yes | Yes | Yes | Yes | Yes |
Syntax
string.substring(start, end)
Parameter Values
| Parameter | Description |
|---|---|
| start | Required. The position where to start the extraction. First character is at index 0 |
| end | Optional. The position (up to, but not including) where to end the extraction. If omitted, it extracts the rest of the string |
Technical Details
| Return Value: | A new String containing the extracted characters |
|---|---|
| JavaScript Version: | ECMAScript 1 |
More Examples
Example
Begin the extraction at position 2, and extract the rest of the string:
var str = "Hello world!";
var res = str.substring(2);
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Example
If "start" is greater than "end", it will swap the two arguments:
var str = "Hello world!";
var res = str.substring(4, 1);
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Example
If "start" is less than 0, it will start extraction from index position 0:
var str = "Hello world!";
var res = str.substring(-3);
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Example
Extract only the first character:
var str = "Hello world!";
var res = str.substring(0, 1);
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Example
Extract only the last character:
var str = "Hello world!";
var res = str.substring(str.length - 1, str.length);
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