Functions

In JavaScript, functions are reusable blocks of code that perform a specific task. They allow you to organize your code into logical units and avoid repetition. Functions can take input values, called parameters, and return a value.

Function Declaration

You can define a function using the function keyword, followed by the function name and a pair of parentheses. Any parameters the function takes are listed inside the parentheses.

Here's an example of a function that greets the user by name:

1function greeting(name) {
2  console.log(`Hello, ${name}!`);
3}

Function Call

Once a function is defined, you can call it by using the function name with a pair of parentheses. If the function takes parameters, you provide the values inside the parentheses.

Here's an example of calling the greeting function with the parameter "John":

1// Function Call
2
3greeting("John");

Output:

1Hello, John!

xxxxxxxxxx

// Function Declaration

​

function greeting(name) {

  console.log(`Hello, ${name}!`);

}

​

// Function Call

​

greeting("John");