Metacharacters and Wildcards: The Core Building Blocks

Metacharacters are special characters that carry meaning beyond their literal character value in regex patterns.

1. The Dot Wildcard (.)

The . (dot) matches any single character except a newline:

// Matches "cat", "bat", "hat", "mat", etc.
/c.t/.test("cat");  // true
/c.t/.test("cut");  // true
/c.t/.test("ct");   // false (no character between c and t)

2. Shorthand Character Classes

Instead of manually typing character ranges, regex provides shorthand classes:

3. Practical Examples

const log = "2026-06-16 Error code: 500";

// Match a date pattern
log.match(/\d{4}-\d{2}-\d{2}/); // ["2026-06-16"]

// Match the status code (3 consecutive digits)
log.match(/\d{3}/); // ["500"]

// Match the word "Error" (only word characters)
log.match(/\w+/g); // ["2026", "06", "16", "Error", "code", "500"]