Object oriented OOJS - javascript-objects

Question

This code works to add up the marks, calculate average and determine if the student is pass/fail. But,can is it a correct Object-oriented technique and whether it can be done in a better way?
function Student(marks1, marks2, marks3, marks4, marks5, marks6) {
// To find the sum total of the marks obtained
var sum = 0;
for (var i = 0; i < arguments.length; i++) {
sum += arguments[i];
}
alert(" Total Marks is " + sum);
console.log(" Total Marks is " + sum);
// To find the average of the marks
var average = sum / 6;
alert(" Average Marks is " + average);
console.log(" Average Marks is " + average);
// To check if the student has passed/failed
if (average > 60) {
alert("Student has passed the exam");
console.log("Student has passed the exam");
} else {
alert("Student has failed the exam");
console.log("Student has failed the exam");
}
}
var myStudent = new Student(58, 64, 78, 65, 66, 58);

Answer 1

Take a look at Introduction to Object-Oriented JavaScript to see how to code using an object-oriented approach to JavaScript.
Note: I would pass in the marks as an array instead of a list of arguments. If you want, you can change the constructor to accept an object, that way you can pass in a variable number of arguments.
function Student(args) {
this.name = args.name || 'Unknown';
this.marks = args.marks || [];
}
Student.prototype.constructor = Student;
Student.prototype.calcSum = function() {
return this.marks.reduce(function(sum, mark) {
return sum + mark;
}, 0);
}
Student.prototype.calcAvg = function() {
return this.calcSum() / this.marks.length;
}
Student.prototype.didPass = function() {
var type = this.calcAvg() > 60 ? 'passed' : 'failed';
return this.name + " has " + type + " the exam.";
}
Student.prototype.toString = function() {
return 'Student { name : "' + this.name + '", marks : [' + this.marks.join(', ') + '] }';
}
// Convienience function to print to the DOM.
function print() { document.body.innerHTML += '<p>' + [].join.call(arguments, ' ') + '</p>'; }
// Create a new student.
var jose = new Student({
name : 'Jose',
marks : [58, 64, 78, 65, 66, 58]
});
print("Total Marks:", jose.calcSum()); // Find the sum total of the marks obtained.
print("Average Marks:", jose.calcAvg()); // Find the average of the marks.
print(jose.didPass()); // Check if the student has passed/failed.
print(jose); // Implicitly call the toString() method.