前端面试-关于变量提升，原型链的js问题

function Foo () {
    getName = ()=>console.log(1);
    return this;
}
Foo.prototype.getName = ()=>{
    console.log(2)
}
Foo.getName=()=>{
    console.log(3)
}
var getName = ()=>{
    console.log(4)
}
function getName () {
    console.log(5)
}
Foo.getName() //3
getName()  //4
Foo().getName()  //1
getName()  //1
new Foo().getName()  //2
new new Foo().getName() //报错： Uncaught TypeError: (intermediate value).getName is not a constructor