main.js

// calculator logic:

let num = 10;
let num2 = 0;

let operator = '/';

if (operator === '+'){
    console.log(num + num2);   
}
else if (operator === '-'){
    console.log(num - num2);

}
else if (operator === '*'){
    console.log(num * num2);
}
else if (operator === '/'){
    if(num2 !=0){
    console.log(num / num2)}
    else {
    console.log("num2 cannot be zero");
}
}
else {
    console.log("invalid operator");
    
}

// -------------------------------------------------------

// student mark analysis:


let mark =30; // set the student mark
let bonus = 4;  

mark += bonus; // adding mark by bonus using assignment operator


let grade; // set the grade using by mark

if (mark >= 90){
    grade = "A";
}
else if(mark >= 70){
    grade = "B";
}
else if(mark >= 50){
    grade = "C";
}
else{
    grade = "F";
}

// get the  mark result of student ,pass or fail using terenory operator

let result = mark >= 50 ? "pass" : "fail";


// set the remarks using switch statement
let remarks;

switch (grade){
    case "A":
        remarks = "excellent";
        break;

    case "B":
        remarks = "good";
        break;

    case "C":
        remarks = "average";
        break;

    default:
        remarks =  "Needs Improvement";
}

// Print results
console.log("Marks:", mark);
console.log("Grade:", grade);
console.log("Result:", result);
console.log("Remark:", remarks);