TypeScript - index of text in string after indicated position

// ONLINE-RUNNER:browser;

​

// We are looking for `is` text position, starting from index 4.

​

//                         This one

//                      |  |

//                      v  v

const text: string = 'This is some example text.';

​

const startIndex: number = 4;

const foundIndex: number = text.indexOf('is', startIndex);

​

console.log(foundIndex); // 5

5