In this tutorial, I will explain how to create and use an empty string array in TypeScript with some examples. I will show you various methods to declare and manipulate string arrays, ensuring you can handle them efficiently in your TypeScript projects.
What is an Empty String Array in TypeScript?
An empty string array in TypeScript is an array that is initialized with no elements but is intended to store strings. This is useful in scenarios where you know you’ll be adding string data later, such as collecting user input or processing data from an API.
When working with arrays, you often need to initialize them as empty and then populate them dynamically.
Check out How to Initialize an Array in TypeScript?
Declare an Empty String Array in TypeScript
There are several ways to declare an empty string array in TypeScript. Let’s explore each method with examples:
Using Square Bracket Syntax
The most common way to declare an empty string array is by using the square bracket syntax. Here is the syntax:
let names: string[] = [];
In this example, names
is an empty string array that can only hold string values. You can add elements to this array later in your code.
Using the Array Generic Type
Another way to declare an empty string array in TypeScript is by using the Array
generic type. This method is more explicit and can be useful in certain coding styles.
let cities: Array<string> = [];
Here, cities
is an empty array that will store string values. This syntax is equivalent to the square bracket syntax but can be preferred for consistency in some codebases.
Initialize with the Array Constructor
You can also use the Array
constructor to create an empty string array in TypeScript. This method is less common but can be useful in certain scenarios.
let states = new Array<string>();
In this case, states
is an empty string array initialized using the Array
constructor. This method is functionally equivalent to the previous examples.
Check out Append Elements to an Array in TypeScript
Adding Elements to an Empty String Array
Once you have declared an empty string array, you can add elements to it using various methods. Let’s look at some examples of adding elements to an empty string array in TypeScript.
Using the push() Method
The push
method adds one or more elements to the end of an empty array in TypeScript.
let fruits: string[] = [];
fruits.push("Apple");
fruits.push("Banana");
console.log(fruits); // Output: ["Apple", "Banana"]
In this example, we start with an empty array fruits
and add two elements using the push
method.
Here is the exact output in the screenshot below:

Using Index Assignment
You can also add elements to an empty array by directly assigning values to specific indices.
let cities: string[] = [];
cities[0] = "New York";
cities[1] = "Los Angeles";
console.log(cities); // Output: ["New York", "Los Angeles"]
Here, we add elements to the cities
array by assigning values to indices 0 and 1.
Check out Check if a TypeScript Array Contains a Specific Value
Using the Spread Operator
The spread operator (...
) allows you to add multiple elements to an empty array in a concise manner in TypeScript.
let states: string[] = [];
states = [...states, "California", "Texas"];
console.log(states); // Output: ["California", "Texas"]
In this example, we use the spread operator to add two elements to the states
array.
Here is the exact output in the screenshot below:

Read Add Elements to an Array in TypeScript
Check if a String Array is Empty in TypeScript
Sometimes, you need to check if an array is empty in TypeScript before performing certain operations. You can do this by checking the array’s length
property.
Using the length Property
The best way to check if an array is empty is by using the length
property in TypeScript.
let names: string[] = [];
if (names.length === 0) {
console.log("The array is empty.");
} else {
console.log("The array is not empty.");
}
In this example, we check if the names
array is empty by comparing its length
property to 0.
Using the Array.isArray() Method
You can also use the Array.isArray
method in combination with the length
property to ensure the variable is an empty array in TypeScript.
let fruits: string[] = [];
if (Array.isArray(fruits) && fruits.length === 0) {
console.log("The array is empty.");
} else {
console.log("The array is not empty.");
}
This method is more robust as it first checks if fruits
is indeed an array before checking its length.
Check out Iterate Over Arrays in TypeScript
Practical Examples
Let’s look at some practical examples of using empty string arrays in TypeScript in real-world scenarios.
Collecting User Input
Suppose you are building a web application where users can enter their favorite movies. You can use an empty string array to collect and store this information.
let favoriteMovies: string[] = [];
function addMovie(movie: string) {
favoriteMovies.push(movie);
}
addMovie("The Shawshank Redemption");
addMovie("The Godfather");
console.log(favoriteMovies); // Output: ["The Shawshank Redemption", "The Godfather"]
In this example, we use the addMovie
function to add user input to the favoriteMovies
array.
Processing API Data
Imagine you are working on an application that fetches data from an API and processes it. You can use an empty string array to store the processed data.
let processedData: string[] = [];
function processData(data: string[]) {
data.forEach(item => {
processedData.push(item.toUpperCase());
});
}
const apiData = ["chicago", "houston", "phoenix"];
processData(apiData);
console.log(processedData); // Output: ["CHICAGO", "HOUSTON", "PHOENIX"]
In this example, we fetch data from an API, process it by converting each item to uppercase, and store it in the processedData
array.
Conclusion
In this tutorial, we explored how to create and use an empty string array in TypeScript. We covered various methods to declare an empty string array, add elements to it, and check if it is empty. We also looked at practical examples of using empty string arrays in real-world scenarios. Do let me know in the comments below if it helps.
I’m Bijay Kumar Sahoo, and I am honored to be awarded the Microsoft MVP. With over 18 years of experience in the IT industry, I got a chance to work on SharePoint Framework (SPFx) development, TypeScript, React, JavaScript, etc. My journey has taken me through esteemed organizations such as TCS, HP, and KPIT, where I have honed my skills and expanded my expertise. Check out more about me here.