There are no Multiple inheritances in JavaScript. In JavaScript every object has a single associated prototype, it cannot dynamically inherit from more than one prototype chain.
Inheriting from two classes can be done by creating a parent object as a combination of two parent prototypes.
The syntax for subclassing makes it possible to do that in the declaration since the right-hand side of the extends clause can be any expression. Thus, you can write a function that combines prototypes according to whatever criteria you like, and call that function in the class declaration.
Multiple inheritances in JavaScript
Simple example code creating a new prototype with the methods of two other prototypes.
<!DOCTYPE html>
<html>
<body>
<script>
var Animal = function() {
this.className = 'Animal';
this.vector = {x: 0, y: 0};
}
var Flying_object = function() {
this.className = 'Flying_object';
this.value = 'some value';
}
function mix(classA, classB) {
var instanceA = new classA(),
instanceB = new classB();
for (var prop in instanceA) {
instanceB[prop] = instanceA[prop];
}
return instanceB;
}
var Bird = function() { this.className = 'Bird'; };
Bird.prototype = mix(Animal, Flying_object);
var instance = new Bird();
console.log(instance);
console.log(instance.className);
console.log(instance.value);
</script>
</body>
</html> Output:
Source: stackoverflow.com
Do comment if you have any doubts or suggestions on this JS inheritance topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version