Working with TypeScript Functions
Working with TypeScript Functions
TypeScript is a powerful and versatile open source programming language that is currently becoming increasingly popular among developers. It adds static typing to JavaScript which brings with it a more robust level of coding and in turn, better quality apps.
TypeScript functions are one of the more efficient ways of coding as they provide users with the ability to create modular and reusable code blocks. In this article, we're going to dive in and explore the basics of working with TypeScript functions.
What Are TypeScript Functions?
Simply put, TypeScript functions are blocks of code that can be reused over and over again in order to perform different tasks. When dealing with larger projects, having functions available to you can save a great amount of time and effort, as you don't need to re-write the same code for every single task.
Creating a Simple Function
To create a simple function in TypeScript, all you need to do is include the keyword “function” followed by the name of the function, the parameters it's going to take in, and the code block. Every function must end with the keyword “return”, to indicate what the function is expected to return. Here's a simple example:
function addNumbers(num1, num2){
let sum = num1 + num2;
return sum;
}
The above function takes two numbers as input, adds them up, and returns the result. It can then be used anywhere else in your code whenever you need to add two numbers together. This saves you from having to type out the same code again and again!
Passing Arguments
When you call a function, you may want to pass arguments to it in order to make the function dynamic and able to serve different purposes. To do this, you'll have to define the parameters of the function when declaring it. Let’s look at an example:
function greetUser(name: string){
console.log(`Hello, ${name}!`);
}
In the example above, we've declared an argument – name – which is of type string. We can now pass in any value for “name” and the function will print out the appropriate message. To call the above function, we would do something like this:
greetUser('John');
Which will print “Hello, John!” to the console.
Return Values
TypeScript functions always return a value. This can either be an explicit value (using the return keyword) or an implicit value (which is the same as the last statement executed). Let's take a look at an example:
function getUserAge(){
let age = 25;
return age;
}
In the example above, the function is implicitly returning the value of “age”, which is 25.
Conclusion
TypeScript functions can be incredibly useful when it comes to making your code easier to manage and maintain. Using functions allows you to easily create modular code that can be reused multiple times, increasing your overall productivity and the quality of your applications.