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# locate-character | |
Get the line and column number of a particular character in a string. | |
## Installation | |
`npm install locate-character`, or get it from [unpkg.com/locate-character](https://unpkg.com/locate-character). | |
## Usage | |
To search for a particular character, using the index or a search string, use `locate`: | |
```js | |
import { locate } from 'locate-character'; | |
const sample = ` | |
A flea and a fly in a flue | |
Were imprisoned, so what could they do? | |
Said the fly, "let us flee!" | |
"Let us fly!" said the flea. | |
So they flew through a flaw in the flue. | |
`.trim(); | |
// Using a character index | |
const index = sample.indexOf('fly'); | |
locate(sample, index); | |
// -> { line: 0, column: 13, character: 13 } | |
// Using the string itself | |
locate(sample, 'fly'); | |
// -> { line: 0, column: 13, character: 13 } | |
// Using the string with a start index | |
locate(sample, 'fly', { startIndex: 14 }); | |
// -> { line: 2, column: 9, character: 76 } | |
``` | |
If you will be searching the same string repeatedly, it's much faster if you use `getLocator`: | |
```js | |
import { getLocator } from 'locate-character'; | |
const locate = getLocator(sample); | |
let location = locate(13); | |
// -> { line: 0, column: 13, character: 13 } | |
location = locate('fly', { startIndex: location.character + 1 }); | |
// -> { line: 2, column: 9, character: 76 } | |
location = locate('fly', { startIndex: location.character + 1 }); | |
// -> { line: 3, column: 8, character: 104 } | |
``` | |
In some situations (for example, dealing with sourcemaps), you need one-based line numbers: | |
```js | |
getLocator(sample, { offsetLine: 1 }); | |
locate(sample, { offsetLine: 1 }); | |
``` | |
There's also an `offsetColumn` option which is less useful in real-world situations. | |
## License | |
MIT | |