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Francisco Moretti
Francisco Moretti

Posted on • Originally published at franciscomoretti.com

Popular Ways To Write JavaScript Functions

What is Function Syntax? 📝

JavaScript offers various ways to define functions, each with its own strengths and use cases. Here are the most commonly used methods:

Function Declaration

Function Declaration provides a straightforward syntax for defining functions.

function functionName(parameters) {
    // Function body
    return expression
}
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Usage: Perfect for defining functions that need to be hoisted, meaning they can be called before they are declared.

Function Expression

Function Expression assigns a function to a variable.

var functionName = function(parameters) {
    // Function body
    return expression
};
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Usage: Useful for anonymous functions or when you want to assign a function to a variable.

Arrow Function (ES6)

Arrow Function introduces a concise syntax.

const functionName = (parameters) => {
    // Function body
    return expression
};
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Usage: Provides a concise syntax, especially handy for short, one-liner functions. It also maintains the lexical this, making it particularly useful for callbacks and event handlers.

Arrow Function with Implicit Return (ES6)

Arrow Function with Implicit Return offers a shorthand for arrow functions. This example returns the expression.

const functionName = (parameters) => expression;
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Usage: Offers a shorthand for arrow functions when the function body consists of a single expression.

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