How to make variable private in Javascript

Javascript does not have access modifier to be precise like other programming languages say Java.So How can we make a variable private.Let us see.

Consider following code snippet

//Immediately invoked function expression

let Person = (function()

{

let _age=0;

return {

firstName:"sangram",

lastName:"desai",

get age()

{

return _age;

},

set age(val)

{

_age = val

}

};

})()

//printing all accessible properties of object

for(let prop in Person)

{

console.log(prop);

}

console.log(Person.firstName)

console.log(Person.lastName)

//public properties

Person.age = 40;

console.log(Person.age)

//private variable

console.log(Person._age)

Output:

firstName

lastName

age

sangram

desai

40

undefined

Here _age is defined outside to make it private property.firstName & lastName are public properties of Person object.we defined age property using getter & setter syntax to access private property _age

We have printed all accessible properties of Person Object which happens to be

firstName

lastName

age

note _age is not there.

Then we try to directly print _age as follows

console.log(Person._age)

It comes out as undefined.