JavaScript Where To

JavaScript code is inserted between tags. You can place scripts in the , in the , or in an external file.

In the <body>

Placing scripts at the bottom of the element improves the display speed, because script interpretation slows down the display.

Example — function called from button

function showMessage() {
    console.log("Button clicked!");
}
showMessage();

In the <head>

Example — function defined in head

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

External JavaScript

Scripts can be placed in external files. External scripts are referenced with a src attribute:

Advantage	Why It Helps
Separation of concerns	HTML and JS are in separate files
Reusability	One script used by many HTML pages
Caching	Browser caches the file for faster loads
Readability	Cleaner HTML markup

External script references

// Reference external scripts with src attribute:
// <script src="https://example.com/js/myScript.js"></script>
// <script src="/js/myScript.js"></script>
// <script src="myScript.js"></script>
console.log("External scripts keep HTML clean!");

📝 Note: You cannot use both src and inline code in the same