What is the string type?

TypeScriptJunior~1 min read

What is the `string` type

The string type in TypeScript represents text data, that is, a sequence of Unicode characters. It is used to store strings - words, sentences, any text values.

Unlike the String object, which is created via the constructor (new String("...")), the primitive string is a true primitive, not an object. TypeScript distinguishes between these two concepts, and you should use the primitive type string.

How to declare a variable of type `string`

There are several ways:

1. Explicit type annotation

javascript

let message: string = "Hello, TypeScript!";

2. Implicit type inference

TypeScript infers the string type on its own when a string value is assigned:

javascript

let greeting = "Hello!"; // automatically: string

3. Using template literals

You can use backticks to substitute expressions:

javascript

let name: string = "Alex";
let welcome: string = `Welcome, ${name}!`;

Usage examples

javascript

// String concatenation
let firstName: string = "Alice";
let lastName: string = "Smith";
let fullName: string = firstName + " " + lastName;

// Getting a character
let firstChar: string = firstName.charAt(0); // "A"

// String length
let length: number = fullName.length; // 11

Important

Use string, not String:

javascript
let s1: string = "text"; // correct let s2: String = new String("text"); // not recommended

Because String is a wrapper object, not a primitive, which can cause unexpected errors in comparisons and checks.

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What is the string type?