Searching for substrings and characters within strings is a common task in programming. Here are some techniques in different languages:

1let str = "Hello World";
2
3// indexOf to find substring  
4let index = str.indexOf("World"); 
5
6// includes to check if substring exists
7let hasHello = str.includes("Hello");

Regular expressions provide powerful pattern matching capabilities. Here is a regex example to match email addresses:

1const pattern = /^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$/;
2const match = pattern.test("john@email.com");

Wildcards like * and ? can be used for glob style pattern matching:

1const files = fs.readdirSync('./*.js'); // matches all .js files

This covers some basic techniques for searching, pattern matching and globbing in different languages. Regular expressions are a powerful tool for advanced string operations.

xxxxxxxxxx

let str = "Hello World";

let index = str.indexOf("World"); // indexOf to find substring

let hasHello = str.includes("Hello"); // includes to check if substring exists

const pattern = /^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$/;

const match = pattern.test("john@email.com"); // regex example to match email addresses