Given this class; how would i iterate over the methods that it includes?
class Animal {
constructor(type){
this.animalType = type;
}
getAnimalType(){
console.log('this.animalType: ', this.animalType );
}
}
let cat = window.cat = new Animal('cat')
What I have tried is the following with no success:
for (var each in Object.getPrototypeOf(cat) ){
console.log(each);
}
You can use Object.getOwnPropertyNames on the prototype:
Object.getOwnPropertyNames( Animal.prototype )
// [ 'constructor', 'getAnimalType' ]
i know, i know, but hey...
const isGetter = ( x, name ) => ( Object.getOwnPropertyDescriptor( x, name ) || {} ).get
const isFunction = ( x, name ) => typeof x[ name ] === "function";
const deepFunctions = x =>
x && x !== Object.prototype &&
Object.getOwnPropertyNames( x )
.filter( name => isGetter( x, name ) || isFunction( x, name ) )
.concat( deepFunctions( Object.getPrototypeOf( x ) ) || [] );
const distinctDeepFunctions = x => Array.from( new Set( deepFunctions( x ) ) );
const userFunctions = x => distinctDeepFunctions( x ).filter( name => name !== "constructor" && !~name.indexOf( "__" ) );
// example usage
class YourObject {
hello() { return "uk"; }
goodbye() { return "eu"; }
}
class MyObject extends YourObject {
hello() { return "ie"; }
get when() { return "soon"; }
}
const obj = new MyObject();
console.log( userFunctions( obj ) ); // [ "hello", "when", "goodbye" ]This is a bit more elaborated but gets methods from the whole prototype chain.
function getAllMethodNames (obj, depth = Infinity) {
const methods = new Set()
while (depth-- && obj) {
for (const key of Reflect.ownKeys(obj)) {
methods.add(key)
}
obj = Reflect.getPrototypeOf(obj)
}
return [...methods]
}