Javascript Variable
Variables are used to store values (name="Ram") or expressions (Sum=x+y).
Before using of variable first we need to declare it. We use keyword var to declare a variable like this:
There are two types of variables:
Global Variable-It has global scope which means, it can be defined anywhere in JavaScript code.
A variable is declared outside the function.
Example
Try Now
Declaring JavaScript global variable within function
To declare JavaScript global variable inside function, we need to use window object.
Example
Now it can be declared inside any function and can be accessed from any function.
Example
Try Now
var name;
- Local Variable
- Global Variable
<script>
functionabc(){
var x=10; //local variable
</script>
<!DOCTYPE html>
<html>
<body>
<script>
var data =200; //global variable
function a(){
document.writeln(data);
}
function b(){
document.writeln(data);
}
a();//calling javascript function
b();
</script>
</body>
</html>
window.value=90;
<!DOCTYPE html>
<html>
<body>
<script>
function a(){
window.value=50; //declare global variable by use of window object
}
function b(){
alert(window.value);//access global variable from other function
}
a();
b();
</script>
</body>
</html>