Math.sqrt(144)

12
console.log("Hello World")

Hello World

var msg = "Hello, World!";
console.log(msg);

Hello, World!

var age = "16";
console.log(age);

16

function logIt(output) {
    console.log(output);
}
logIt(msg);

Hello, World!

function logItType(output) {
    console.log(typeof output, ";", output);
}
console.log("Looking at dynamic nature of types in JavaScript")
logItType("hello"); 
logItType(2022);    
logItType([1, 2, 3]);

Looking at dynamic nature of types in JavaScript
string ; hello
number ; 2022
object ; [ 1, 2, 3 ]

function Person(name, ghID, classOf) {
    this.name = name;
    this.ghID = ghID;
    this.classOf = classOf;
    this.role = "";
}

// define a setter for role in Person data
Person.prototype.setRole = function(role) {
    this.role = role;
}

// define a JSON conversion "method" associated with Person
Person.prototype.toJSON = function() {
    const obj = {name: this.name, ghID: this.ghID, classOf: this.classOf, role: this.role};
    const json = JSON.stringify(obj);
    return json;
}

// make a new Person and assign to variable teacher
var teacher = new Person("Mr M", "jm1021", 1977);  // object type is easy to work with in JavaScript
logItType(teacher);  // before role
logItType(teacher.toJSON());  // ok to do this even though role is not yet defined

// output of Object and JSON/string associated with Teacher
teacher.setRole("Teacher");   // set the role
logItType(teacher); 
logItType(teacher.toJSON());

object ; Person { name: 'Mr M', ghID: 'jm1021', classOf: 1977, role: '' }
string ; {"name":"Mr M","ghID":"jm1021","classOf":1977,"role":""}
object ; Person { name: 'Mr M', ghID: 'jm1021', classOf: 1977, role: 'Teacher' }
string ; {"name":"Mr M","ghID":"jm1021","classOf":1977,"role":"Teacher"}

var students = [ 
    new Person("Luka", "LukaVDB", 2024),
    new Person("Jishnu", "JishnuS420", 2024),
    new Person("Edwin", "EdwinKuttappi", 2024),
    new Person("Emaad", "Emaad-Mir", 2025),
    
];

// define a classroom and build Classroom objects and json
function Classroom(teacher, students){ // 1 teacher, many student
    // start Classroom with Teacher
    teacher.setRole("Teacher");
    this.teacher = teacher;
    this.classroom = [teacher];
    // add each Student to Classroom
    this.students = students;
    this.students.forEach(student => { student.setRole("Student"); this.classroom.push(student); });
    // build json/string format of Classroom
    this.json = [];
    this.classroom.forEach(person => this.json.push(person.toJSON()));
}

// make a CompSci classroom from formerly defined teacher and students
compsci = new Classroom(teacher, students);

// output of Objects and JSON in CompSci classroom
logItType(compsci.classroom);  // constructed classroom object
logItType(compsci.classroom[0].name);  // abstract 1st objects name
logItType(compsci.json[0]);  // show json conversion of 1st object to string
logItType(JSON.parse(compsci.json[0]));

object ; [ Person { name: 'Mr M', ghID: 'jm1021', classOf: 1977, role: 'Teacher' },
  Person { name: 'Luka', ghID: 'LukaVDB', classOf: 2024, role: 'Student' },
  Person {
    name: 'Jishnu',
    ghID: 'JishnuS420',
    classOf: 2024,
    role: 'Student' },
  Person {
    name: 'Edwin',
    ghID: 'EdwinKuttappi',
    classOf: 2024,
    role: 'Student' },
  Person {
    name: 'Emaad',
    ghID: 'Emaad-Mir',
    classOf: 2025,
    role: 'Student' } ]
string ; Mr M
string ; {"name":"Mr M","ghID":"jm1021","classOf":1977,"role":"Teacher"}
object ; { name: 'Mr M', ghID: 'jm1021', classOf: 1977, role: 'Teacher' }

Classroom.prototype._toHtml = function() {
    // HTML Style is build using inline structure
    var style = (
      "display:inline-block;" +
      "border: 2px solid grey;" +
      "box-shadow: 0.8em 0.4em 0.4em grey;"
    );
  
    // HTML Body of Table is build as a series of concatenations (+=)
    var body = "";
    // Heading for Array Columns
    body += "<tr>";
    body += "<th><mark>" + "Name" + "</mark></th>";
    body += "<th><mark>" + "GitHub ID" + "</mark></th>";
    body += "<th><mark>" + "Class Of" + "</mark></th>";
    body += "<th><mark>" + "Role" + "</mark></th>";
    body += "</tr>";
    // Data of Array, iterate through each row of compsci.classroom 
    for (var row of compsci.classroom) {
      // tr for each row, a new line
      body += "<tr>";
      // td for each column of data
      body += "<td>" + row.name + "</td>";
      body += "<td>" + row.ghID + "</td>";
      body += "<td>" + row.classOf + "</td>";
      body += "<td>" + row.role + "</td>";
      // tr to end line
      body += "<tr>";
    }
  
     // Build and HTML fragment of div, table, table body
    return (
      "<div style='" + style + "'>" +
        "<table>" +
          body +
        "</table>" +
      "</div>"
    );
  
  };
  
  // IJavaScript HTML processor receive parameter of defined HTML fragment
  $$.html(compsci._toHtml());
</table></div> </div> </div> </div> </div> </div> </div>
Name GitHub ID Class Of Role
Mr M jm1021 1977 Teacher
Luka LukaVDB 2024 Student
Jishnu JishnuS420 2024 Student
Edwin EdwinKuttappi 2024 Student
Emaad Emaad-Mir 2025 Student