java script learning: statements

JavaScript Statements

JavaScript statements are "commands" to the browser. Statements informs to the browser what to do.

· Semicolon separates JavaScript statements. Every statement ends with a semicolon.

· Using semicolon we can write many statements in one line.

· In javascripts semicolon is optional

JavaScript Programs(code)

· JavaScript code (or just JavaScript) is a sequence(collection) of JavaScript statements.

· Each statement is executed by the browser in the sequence they are written.

This example will manipulate two HTML elements:

Example

<!DOCTYPE html>

<html>

<body>

<p id="demo">A Paragraph.</p>

document.getElementById("demo").innerHTML="Hello World";

document.getElementById("myDIV").innerHTML="JavaScript Statements";

</script>

</body>

</html>

JavaScript Code Blocks

The purpose of a block is to make the sequence of statements execute together.

A good example of statements grouped together in blocks, are JavaScript functions.

This example will run a function that will manipulate two HTML elements:

Example

<!JavaScript code blocks-->

<html>

<body>

<h1>My Web Page</h1>

<p id="myPar">I am a paragraph.</p>

<div id="myDiv">I am a div.</div>

<p>

<button type="button" onclick="myFunction()">Try it</button>

</p>

<script>

function myFunction()

{

document.getElementById("myPar").innerHTML="Good Morning";

document.getElementById("myDiv").innerHTML="How are you?";

}

</script>

<p>When you click on "Try it", the two elements will change.</p>

</body>

</html>

java script learning