![]() You start by using the keyword " function," followed by the function name and a set of parentheses. They also allow for code reuse and make it easier to understand and maintain large codebases. Functions can take input in the form of parameters and can return a value or output.įunctions help you organize and structure your code. The syntax for creating a function in JavaScript is quite simple. JavaScript functions are basically used to encapsulate logic, making that code more reusable and easier to understand. Function SyntaxĪ function is a block of code that performs a specific task. ![]() In this article, we will explore the basics of functions in JavaScript and how you can use them effectively in your code. You can think of functions as a way to group a set of instructions together and execute them as a single unit. It is supported by all major web browsers, and it is an essential technology for front-end web development.įunctions are one of the building blocks of JavaScript programming for creating web applications. You can use it to create web and mobile applications, browser extensions, and other software. JavaScript is a high-level, interpreted language used on the client side, meaning it runs in the user's web browser. Its ability to run on both client-side and server-side makes it a versatile tool that has become an essential tool for web developers. ![]() In my next post, I’ll dive a bit deeper into Arrow Function parameters.JavaScript is a widely-used programming language that is essential for web development. When the function body has a single expression, an object can be implicitly returned if it is wrapped in parentheses.When the function body has a single expression, the implied return value is the expression.When the function body has a single expression, no curly braces are required.The “function” keyword has been replaced by: “=>”.The order of the parameter(s) and the “function” keyword are switched.The biggest changes you’ll notice right away are: But the goal here was to simply provide a gentle introduction to the syntax. This article merely scratches the surface of what is possible in ECMAScript 6 Arrow functions. The beauty of this approach is that the single-line version of arrow functions allows you to omit the “return” statement, so we just provide the object that we want to return in the parentheses. Inside of these parentheses is an object. What differs here is that the function body is wrapped in a set of parentheses. In Example # 3, we’ve gone back to a single-line version of the addOne arrow function. But what if you want to return an object in this scenario? Since the curly braces can be omitted, you simply need to wrap the object you return in parentheses. While multi-expression function bodies are perfectly acceptable, it is likely that in many cases, you’ll want to leverage that streamline single-expression (hence single-line) syntax. One of the main benefits of arrow function is the terse syntax. Returning an Object in a Single-Expression Function Body In Example # 2B, we get the expected behaviour because we specify a return value. So, just as with any function in JavaScript, a function that does not specify a return value returns “undefined” (the exception to this rule is a constructor function, which can return any object but returns the instance object when no return value is specified). This happens because the function body of addOne has curly braces, but we have not explicitly returned a value. In Example # 2A, the return value of addOne(2) is: “undefined”. This is why the return value of our arrow function is the passed-in parameter plus one, even though there is no “return” statement. Also, when the function body consists of a single expression, the implicit return value of the function is the result of that expression. When the arrow function consists of more than one expression, then curly braces are required. In this case, the curly braces can be omitted. This is because the body of our arrow function consisted of one expression. ![]() In Example # 1B, you may have noticed the absence of the curly braces. This equal+greater than character combination replaces the “function” keyword. First, we next have the single parameter: “someNumber”. But it’s after the assignment operator, that things start to look quite different. The “var addOne =” portion of the code should be familiar to you. Now in Example # 1B, we have accomplished the exact same result, using arrow function syntax. That is, the function “addOne” takes a single parameter (a number), and returns that number plus one. In Example # 1A, we have the standard syntax you would use when creating an anonymous function expression.
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