An operator is a symbol which helps the user to command the computer to do a certain mathematical or logical manipulations. Operators are used in the program to operate on data and variables.
Arithmetic Operators
Arithmetic operators work on one or more numeric values yielding a single result.
+ Addition
- Subtraction
* Multiplication
/ Division
% Modulus
++ Increment by 1
– Decrement by 1 (more…)
Variables
Variables are memory locations that are given names and can be assigned values. We use variables to store data in memory for later use.
Variable names
Once a value is stored in a variable it can be accessed using the variable name. A variable name can consist of alphanumeric characters and the underscore. It cannot begin with a numeral, though. Note that variable names are case sensitive and first_name is not the same as FIRST_name.
Valid variable names
first_name
name2
_car
Average (more…)
The example demonstrates how to use JavaSript to write text on a web page.
<html>
<body>
<script type=”text/javascript”>
document.write(”<h1>Hello World!</h1>”);
</script>
</body>
</html>
Output:
Hello World!
JavaScript works with HTML to bring interactivity to otherwise static documents and can be embedded inside HTML documents in three ways:
Using the <SCRIPT> tags
JavaScript code is most commonly included between <SCRIPT> - </SCRIPT> tags. For example:
<HTML>
<HEAD>
<TITLE>Page title</TITLE>
</HEAD> <BODY>
<SCRIPT LANGUAGE=”JAVASCRIPT” TYPE=”TEXT/JAVASCRIPT”>
<!–
some javascript code
//–>
</SCRIPT>
</BODY>
</HTML> (more…)