JavaScript Variables
An Example of Variable Use
Variable
Variables are used to store data. This example shows you how:
<html>
<body>
<script type="text/javascript">
var name = "WECT"
document.write(name)
document.write("<h1>"+name+"</h1>>")
</script>
This example declares a variable, assigns a value to it, and then displays the variable.<P>
Then the variable is displayed one more time, only this time within a heading element.
</body>
</html>
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Variables
A variable is a "container" for information you want to store. A
variable's value can change during the script. You can refer to a variable by
name to see its value or to change its value.
Rules for Variable names:
- Variable names are case sensitive
- They must begin with a letter or the underscore character
Declare a Variable
You can create a variable with the var statement:
You can also create a variable without the var statement:
Assign a Value to a Variable
You assign a value to a variable like this:
Or like this:
The variable name is on the left side of the expression and the value you
want to assign to the variable is on the right. Now the variable
"strname" has the value "Hege".
Lifetime of Variables
When you declare a variable within a function, the variable can only be
accessed within that function. When you exit the function, the
variable is destroyed. These variables are called local variables. You can have
local variables with the same name in different functions, because each is
recognized only by the function in which it is declared.
If you declare a variable outside a function, all the functions on your page can
access it. The lifetime of these variables starts when they are declared, and
ends when the page is closed.
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