TypeScript String match()

In this chapter, we will explore the match() method in TypeScript. This method is a built-in function that helps in matching a string against a regular expression. Understanding how to use match() is useful for pattern matching and extracting substrings based on specific patterns.

Table of Contents

1. Definition
2. Syntax
3. Examples
4. Conclusion

1. Definition

The match() method retrieves the result of matching a string against a regular expression. It returns an array of matched substrings or null if no matches are found.

2. Syntax

string.match(regexp);

Parameters

• regexp: A regular expression object. If a non-RegExp object is passed, it is implicitly converted to a RegExp with a global search.

Return Value

The method returns an array containing the matches, or null if no match is found.

3. Examples

Let's look at some examples to understand how match() works in TypeScript.

Example 1: Basic Usage

In this example, we use match() to find all occurrences of a pattern in a string.

let str: string = "Hello, TypeScript! TypeScript is awesome!";
let result = str.match(/TypeScript/g);
console.log(result); // Output: [ 'TypeScript', 'TypeScript' ]

Example 2: Using match() without Global Flag

In this example, we use match() without the global flag to find the first occurrence of a pattern in a string.

let str: string = "Hello, TypeScript! TypeScript is awesome!";
let result = str.match(/TypeScript/);
console.log(result); // Output: [ 'TypeScript', index: 7, input: 'Hello, TypeScript! TypeScript is awesome!', groups: undefined ]

Example 3: Matching Digits in a String

In this example, we use match() to find all digit characters in a string.

let str: string = "The year is 2024.";
let result = str.match(/\d+/g);
console.log(result); // Output: [ '2024' ]

Example 4: Matching Words in a String

In this example, we use match() to find all words in a string.

let str: string = "Hello, TypeScript!";
let result = str.match(/\w+/g);
console.log(result); // Output: [ 'Hello', 'TypeScript' ]

Example 5: No Match Found

In this example, we use match() with a pattern that does not exist in the string.

let str: string = "Hello, TypeScript!";
let result = str.match(/JavaScript/);
console.log(result); // Output: null

4. Conclusion

In this chapter, we explored the match() method in TypeScript, which is used to match a string against a regular expression. We covered its definition, syntax, parameters, return value, and provided several examples to demonstrate its usage. Understanding how to use match() effectively can help in various string manipulation tasks in TypeScript, especially when working with patterns and extracting substrings based on specific criteria.