JavaScript is a popular scripting language that control the behavior of the webpage using script.
Where to Place JavaScript Code?
You can place your JavaScript code in two places.
- Inside the HTML document
- Use an external file for JavaScript and link to HTML document.
JavaScript inside HTML page
<script>
document.write("Hello world");
<script/>External JavaScript File
For external JavaScript file, you have to link it to HTML document.
<script src="demo.js"></script>
Output Method in JavaScript
JavaScript programming output method in four different ways. They are listed below.
<mark style="background-color:rgba(0, 0, 0, 0);color:#bc1212" class="has-inline-color">document.getElementById(“demo”).innerHTML = ‘hello”;</mark><mark style="background-color:rgba(0, 0, 0, 0);color:#ba1010" class="has-inline-color">console.log(“Hello”);</mark><mark style="background-color:rgba(0, 0, 0, 0);color:#b61414" class="has-inline-color">alert(“hello”);</mark><mark style="background-color:rgba(0, 0, 0, 0);color:#b81414" class="has-inline-color">document.write(“Hello”);</mark>
The first method is using <mark style="background-color:rgba(0, 0, 0, 0);color:#b91515" class="has-inline-color">HTML DOM</mark> and <mark style="background-color:rgba(0, 0, 0, 0);color:#c70d0d" class="has-inline-color">selector API</mark> functions like <mark style="background-color:rgba(0, 0, 0, 0);color:#b01414" class="has-inline-color">getElementById</mark>, etc.
The second method prints the output to the browser console.
The third method usually used for creating error or warning for program that is displayed to users as a popup box.
The last method, is <mark style="background-color:rgba(0, 0, 0, 0);color:#bb1212" class="has-inline-color">document.write()</mark>, that simply write to the document body wiping everything out except the output.