prototype

Prototypes

Prototypes are a way to make our code more efficient, especially when using constructors. Take the following code for example…

function Animal(name){
    this.animalName = name;
    this.grunt = function(){
        console.log(‘ugh!’);
    };
}
let gorilla = new Animal(‘Bongo’);
gorilla.grunt(); 

Imagine we have one thousand animals. When we use the “new” keyword, the data basically gets copied to the new object. So we would create one thousand grunt functions. Maybe we do not need one thousand and only want one to save memory and improve performance. We have to change our constructor a bit…

function Animal(name){
    this.animalName = name;
}
Animal.prototype.grunt = function(){  
    console.log(‘ugh!’);
};
let gorilla = new Animal(‘Bongo’); gorilla.grunt(); 

The output will be the same…”ugh!”. The difference is we have saved memory and improved performance if we want to create a whole bunch of animals. We can also use the “this” keyword in prototype…

function Animal(name){
    this.animalName = name;
}
Animal.prototype.grunt = function(){
    console.log(‘ugh!…says ’ + this.animalName);
};
let gorilla = new Animal(‘Bongo’);
gorilla.grunt(); 

Here the output will be “ugh!…says Bongo”

Happy Coding!

Clay Hess

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