To create a new function, use the function keyword. Provide a name for the function and define any arguments it should accept:

function functionName(arguments) {
  // code block
}

The structure of a function definition includes:

• The function keyword;
• The function name, typically in camelCase like variables;
• Arguments enclosed in parentheses ();
• A code block within curly brackets {}.

Arguments

Functions have their own data storage space. Arguments are values passed to a function, which the function uses as variables. These arguments cease to exist when the function finishes executing.

To define arguments, assign a name to each one:

// Function without arguments
function first() {}

// Function with one argument
function second(argument) {}

// Function with multiple arguments
function third(argument1, argument2, argument3) {}

If a function accepts multiple arguments, separate them with commas (,).

Note

Arguments are used like variables inside the function's code block.

Function calling

To use a function, call it using parentheses () and provide the necessary arguments if the function expects any: