String.prototype.substr()
Returns a portion of a string starting at an index for a given length (legacy).
Syntax
str.substr(start, length)Parameters
| Name | Type | Required | Description |
|---|---|---|---|
start | number | Yes | Index to start from. Negative counts from the end. |
length | number | No | Number of characters to extract. Defaults to the rest of the string. |
Returns
string — A new string containing the extracted section.
Examples
console.log('hello'.substr(1, 3));
Output
ell
console.log('hello'.substr(-2));
Output
lo
Notes
Deprecated/legacy - kept only for web compatibility. Prefer `slice` or
`substring` in new code. The second argument is a length, not an end index.
Browser & runtime support
| Environment | Since version |
|---|---|
| chrome | 1.0 |
| firefox | 1.0 |
| safari | 1.0 |
| edge | 12 |
| node | 0.10 |