## Why Use Functions?
Repeating code makes programs long and hard to maintain. Functions let you group commands into a reusable block, reducing repetition and making your code cleaner.

## How to call Functions?
To **call** a function, simply use its name followed by parentheses, placing any required arguments inside those parentheses. 

In the example below, the `greet` function is called on line 5 by adding parentheses to its name and passing **"Alice"** as the name argument.

### A Simple Function Example


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

greet("Alice");

Here’s what happens when you call `greet("Alice")`:

1. JavaScript looks for the function named `greet`.
2. It passes the string **"Alice"** as the argument for the parameter `name`.
3. Inside the function, the console.log statement concatenates "Hello, ", the value "Alice", and "!" to create the full greeting.
4. The final message **"Hello, Alice!"** is then printed to the console.


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Using Functions

Why Use Functions?

How to call Functions?

A Simple Function Example

Using Functions

Why Use Functions?

How to call Functions?

A Simple Function Example

解答