String type behavior in Typescript

Introduction

Strings hold text in programs. Understanding how they behave helps you work with words and sentences easily.

When you want to store a name or message.

When you need to join words together.

When you want to check if a word contains certain letters.

When you want to change text to uppercase or lowercase.

When you want to find the length of a sentence.

Syntax

Typescript

let variableName: string = "your text here";

Strings are written inside double quotes "", single quotes '', or backticks `` for template strings.

TypeScript uses string type to represent text values.

Examples

Simple string assignment using double quotes.

Typescript

let greeting: string = "Hello";

String can also use single quotes.

Typescript

let name: string = 'Alice';

Template string using backticks allows embedding variables.

Typescript

let message: string = `Hi, ${name}!`;

An empty string has no characters but is still a string.

Typescript

let empty: string = "";

Sample Program

This program shows how to create strings, join them, find length, convert to uppercase, and check if a substring exists.

Typescript

let firstName: string = "John";
let lastName: string = "Doe";
let fullName: string = `${firstName} ${lastName}`;

console.log("Full name:", fullName);
console.log("Length of full name:", fullName.length);
console.log("Uppercase:", fullName.toUpperCase());
console.log("Contains 'Doe'?:", fullName.includes("Doe"));

Important Notes

Strings in TypeScript are immutable, meaning you cannot change a character directly.

Use string methods like toUpperCase(), includes(), and length to work with strings.

Summary

Strings store text and use the string type in TypeScript.

You can create strings with quotes or backticks for templates.

Use built-in methods to check, change case, or find length of strings.