class vs OLOO

ex1.js

class Foo {
  constructor(x,y,z) {
    Object.assign(this,{ x, y, z });
  }
  
  hello() {
    console.log(this.x + this.y + this.z);
  }
}

var instances = [];

for (var i=0; i<500; i++) {
  instances.push(
    new Foo(i,i*2,i*3)
  );
}

instances[37].hello();  // 222

ex2.js

var Foo = {
  hello() {
    console.log(this.x + this.y + this.z);
  }
};

function OD(prot,obj) { return Object.assign(Object.create(prot),obj); }

var instances = [];

for (var i=0; i<500; i++) {
  instances.push(
    OD(Foo,{ x: i, y: i*2, z: i*3 })
  );
}

instances[37].hello();  // 222

ex3.js

function Foo(x,y,z) {
  return {
    hello() {
      console.log(this.x + this.y + this.z);
    },
    x,
    y,
    z
  };
}

var instances = [];

for (var i=0; i<500; i++) {
  instances.push(
    Foo(i,i*2,i*3)
  );
}

instances[37].hello();  // 222