Encapsulation in Javascript
Even though Javascript is not a true object oriented language there are 2 popular features to enable encapsulation in Javascript.
Encapsulation refers to the bundling of data with the methods that operate on that data
- Closure
- Classes
1. Using closure
A closure is the combination of a function and the lexical environment within which that function was declared. This environment consists of any local variables that were in-scope at the time the closure was created.
Sample
function Counter() {
var count = 0; function increment() {
count +=1;
} function getCount() {
return count;
}return {
increment:increment,
getCount:getCount
};
}Usage:
const myCounter = Counter();myCounter.increment();console.log(
myCounter.getCount()
);`
2. Using Classes
Classes introduced in ES6. Classes are a template for creating objects. They encapsulate data with code to work on that data.
Sample
class Counter {
count = 0
increment () {
this.count += 1;
}
getCount () {
return this.count
}
}Usage:const myCounter = new Counter();
myCounter.increment();console.log(
myCounter.getCount()
);
Conclusion
Closures don’t have to worry about the context that this is referring to hence offer simplicity.
Meanwhile, classes tend to be slightly more performant if we are going to be creating multiple instances of an object.
If we are creating multiple instances of an object, classes will best suit our needs. Meanwhile, if we don’t plan to create multiple instances, the simplicity of closures may be a better fit for our project.
