| # 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 | |