I have a simple function, I am trying to access the instance variable. But it's giving me some error. How can I access instance variable in Javascript ? I tried below method, but not working
function Test(){
var a=10;
}
var test=new Test();
test.a=20;
For some reason I don't want to go with the following way:
var Test={
a:''
}
You declared a as a variable local to that function, so there is no way to access it outside (as you currently have it)
If you want a to be an instance variable attach it to the object
function Test(){
this.a=10;
}
var test=new Test();
test.a=20;
var syntax still allows one to access the variable using from outside the object using test.a. Am I missing something here?
Change it to this :
function Test(){
this.a=10;
}
Here a good documentation on the subject : Introduction to Object-Oriented JavaScript
Existing answers tell you how to do it by making a a public property. If you really need a private variable, use the following code. The main reason you would use this instead of a public property is to prevent callers from setting a to invalid values.
function Test() {
var a = 10;
this.setA = function(val) {
a = val;
};
this.getA = function(val) {
return a;
};
}
var t = new Test();
t.setA(80);
t.getA(); // 80
this.a=10instead