How to create object in javaScript?

//1) JavaScript Object by object literal

var emp={id:201,name:"John",salary:60000};
console.log(emp.id+" "+emp.name+" "+emp.salary);

//2) By creating instance of Object

var emp1=new Object();
emp1.id=908;
emp1.name="Kumar";
emp1.salary=45000;

console.log(emp1.id+" "+emp1.name+" "+emp1.salary);

//3) By using an Object constructor

function student(id,name,salary)
{
this.id=id;
this.name=name;
this.salary=salary;
}

s1=new student(1001,"Maichael",90000);
console.log(s1.id+" "+s1.name+" "+s1.salary);