Javascript variables can be local or global scoped depending upon how the are declared. In HTML all global scoped variables becomes part of window object. Here are some variable declaration approaches.
| Declaration | Global/local | Comments |
|---|---|---|
| var g1 = “something”; //outside function |
global | typical use |
| g1=”something”; //outside function |
global | better to use var |
| var lv1=”something”; //inside function |
local | typical use |
| g3=”something”; //inside function |
gloval | its better to avoid. Or use window.g3 = “something” |
Here is an example containing local and global variables.
<script type="text/javascript">
var g1 = "global value1";
g2 = "global value2";
function f1() {
var lv1 = "local value1";
g3 = "gloval value3";
document.write("==In function f1==<br/>");
document.write("g1=" + g1 + "<br/>");
document.write("g2=" + g2 + "<br/>");
document.write("g3=" + g3 + "<br/>");
document.write("lv1=" + lv1 + "<br/>");
}
f1();
document.write("==outside function f1==<br/>");
document.write("g1=" + g1 + "<br/>");
document.write("g2=" + g2 + "<br/>");
document.write("g3=" + g3 + "<br/>");
document.write("typeof(lv1)=" + typeof(lv1) + "<br/>");
document.write("==using window to access global variables==<br/>");
document.write("window.g1=" + window.g1 + "<br/>");
document.write("window.g2=" + window.g2 + "<br/>");
document.write("window.g3=" + window.g3 + "<br/>");
</script>
