find index of a pattern in typescript

There are different ways to find the index of a pattern in a string in TypeScript, but one common approach is to use regular expressions and the search() method of strings. Here's an example:

index.ts
const str = "The quick brown fox jumps over the lazy dog";
const pattern = /fox/;
const index = str.search(pattern);
console.log(index); // outputs 16
151 chars
5 lines

In this code, we define a string str and a regular expression pattern that matches the word "fox". Then, we call the search() method on str and pass the pattern as an argument. The search() method returns the index of the first match, or -1 if no match is found.

Alternatively, you can use the indexOf() method with a string pattern, like this:

index.ts
const str = "The quick brown fox jumps over the lazy dog";
const pattern = "fox";
const index = str.indexOf(pattern);
console.log(index); // outputs 16
152 chars
5 lines

This code produces the same result as the previous example. However, using indexOf() with strings may not be as flexible as using regular expressions, since you can only search for exact matches of the pattern.