To define a parameter in a JavaScript function, we simply include it within the parentheses following the function name. Let’s take a look at a basic example:

function greet(name) {
  console.log("Hello, " + name + "!");
}

greet("John");

In the above example, we define a function called greet that takes a single parameter name. Inside the function body, we use the console.log function to display a personalized greeting to the provided name. When we call the greet function with the argument "John", it will output Hello, John!.

We can also define multiple parameters in a JavaScript function by separating them with commas:

function addNumbers(num1, num2) {
  return num1 + num2;
}

console.log(addNumbers(5, 10));

In the above example, we define a function addNumbers that takes two parameters num1 and num2. Inside the function, we use the return keyword to specify that the result of adding num1 and num2 should be returned. When we call the addNumbers function with the arguments 5 and 10, it will output 15 to the console.

Parameters can also have default values, which are used when the arguments are not provided:

function incrementNumber(num, increment = 1) {
  return num + increment;
}

console.log(incrementNumber(5)); // Outputs 6
console.log(incrementNumber(10, 5)); // Outputs 15

In the above example, we define a function incrementNumber with two parameters num and increment. The increment parameter has a default value of 1, so if we call the function without providing a second argument, it will use the default value. When we call the incrementNumber function with the argument 5, it will output 6. Similarly, when we provide 10 and 5 as arguments, it will output 15.

Using parameters in JavaScript functions allows us to write reusable code that can adapt to different input values. By leveraging the power of parameters, we can make our functions more flexible and versatile, improving the overall functionality of our JavaScript applications.

#JavaScript #Functions