Javascript 2 - Conditionals and Loops

Part 1

Task 1.1: Check for Valid Floor Numbers in a Building

Open HTML File

<!DOCTYPE html>
<html>
<head>
    <title>Task 1.1</title>
    <script>
        function init() {
            var x = parseInt(prompt("Please enter a floor number:"));
            var isValid = false;
            
            // Check if input is between 1 and 50
            if (x >= 1 && x <= 50) {
                // Check for number 13, and digit 4 in ones and tens places
                if (x !== 13 && (x % 10 !== 4) && (Math.floor(x / 10) !== 4)) {
                    isValid = true;
                }
            }
            
            if (isValid) {
                document.getElementById("result").innerHTML = "Welcome! Please enter! Take the elevator to go to floor " + x;
            } else {
                document.getElementById("result").innerHTML = "Your input " + x + " is NOT a valid floor number!";
            }
        }
    </script>
</head>
<body onload="init();">
    <div id="result"></div>
</body>
</html>

Task 1.2: List a Series of Numbers

Open HTML File

<!DOCTYPE html>
<html>
<head>
    <title>Task 1.2</title>
    <script>
        function init() {
            var i, N, s;
            N = 10;
            s = "The integers from 1 to " + N + " are listed below: <br/>";
            
            for (i = 1; i <= N; i++) {
                s = s + i + "<br/>";
            }
            
            document.getElementById("result").innerHTML = s;
        }
    </script>
</head>
<body onload="init();">
    <div id="result"></div>
</body>
</html>

Task 1.3: Label an Integer if It is Divisible by Another Integer

Open HTML File

<!DOCTYPE html>
<html>
<head>
    <title>Task 1.3</title>
    <script>
        function init() {
            var i, N, s, userNum;
            N = 10;
            userNum = parseInt(prompt("Enter a number to check divisibility:"));
            
            s = "The integers from 1 to " + N + " are listed below: <br/>";
            s += "@ the integer is divisible by 2 <br/>";
            s += "% the integer is divisible by 5 <br/>";
            s += "# the integer is divisible by " + userNum + " <br/>";
            
            for (i = 1; i <= N; i++) {
                s = s + i;
                if (i % 2 === 0) {
                    s += "@";
                }
                if (i % 5 === 0) {
                    s += "%";
                }
                if (i % userNum === 0) {
                    s += "#";
                }
                s += "<br/>";
            }
            
            document.getElementById("result").innerHTML = s;
        }
    </script>
</head>
<body onload="init();">
    <div id="result"></div>
</body>
</html>

Part 2

Task 2.1: Valid Floors with Elevator Directions

Open HTML File

<!DOCTYPE html>
<html>
<head>
    <title>Task 2.1</title>
    <script>
        function init() {
            var x = parseInt(prompt("Please enter a floor number:"));
            var isValid = false;
            
            if (x >= 1 && x <= 50) {
                if (x !== 13 && (x % 10 !== 4) && (Math.floor(x / 10) !== 4)) {
                    isValid = true;
                }
            }
            
            var message = "";
            if (isValid) {
                message = "Welcome! Please enter! <br/>";
                if (x >= 1 && x <= 15) {
                    message += "Please proceed to take the lift on the left to go to floor " + x;
                } else if (x >= 16 && x <= 28) {
                    message += "Please proceed to take the lift on the middle to go to floor " + x;
                } else if (x >= 29 && x <= 50) {
                    message += "Please proceed to take the lift on the right to go to floor " + x;
                }
            } else {
                message = "Your input " + x + " is NOT a valid floor number!";
            }
            
            document.getElementById("result").innerHTML = message;
        }
    </script>
</head>
<body onload="init();">
    <div id="result"></div>
</body>
</html>

Task 2.2: Multiple Conditions Labeling (1 to 50)

Open HTML File

<!DOCTYPE html>
<html>
<head>
    <title>Task 2.2</title>
    <script>
        function init() {
            var i, N, s;
            N = 50; 
            
            s = "The integers from 1 to " + N + " are listed below: <br/>";
            s += "^ the integer is divisible by 2 but not divisible by 3 <br/>";
            s += "* the integer is a valid floor number <br/>";
            
            for (i = 1; i <= N; i++) {
                s += i;
                
                // Divisible by 2 but not 3
                if (i % 2 === 0 && i % 3 !== 0) {
                    s += "^";
                }
                
                // Valid floor check
                var isValidFloor = false;
                if (i !== 13 && (i % 10 !== 4) && (Math.floor(i / 10) !== 4)) {
                    isValidFloor = true;
                }
                
                if (isValidFloor) {
                    s += "*";
                }
                
                s += "<br/>";
            }
            
            document.getElementById("result").innerHTML = s;
        }
    </script>
</head>
<body onload="init();">
    <div id="result"></div>
</body>
</html>