Conditional Statements Part 1

Conditional statements are used to direct the flow of the program.

if statements

These are often used to branch conditions. This example outputs through HTML using docuemtn.

%%html

<output id="output"></output>

<script>
function intializeData(data = null) {
    // Define default values
    let scaleFactor = 9/16;
    let animationRate = 1;
    let position = [0, 0];

    // Check if data is provided
    if (data) {
        scaleFactor = data.SCALE_FACTOR || scaleFactor;
        animationRate = data.ANIMATION_RATE || animationRate;
        position = data.INIT_POSITION || position;
    }

    document.getElementById("output").innerHTML = `
        <p>Scale Factor: ${scaleFactor}</p>
        <p>Animation Rate: ${animationRate}</p>
        <p>Initial Position: ${position}</p>
    `;
}

var data = {
    SCALE_FACTOR: 1/1,
    ANIMATION_RATE: 25,
    INIT_POSITION: [100, 100]
}

// Uncomment one of the following lines to test the if statement in the function
//intializeData();
intializeData(data);

</script>

switch case statement

These are often used to branch code when there are a lot of options.

%%javascript

class GameObject {
    constructor() {
        this.velocity = { x: 0, y: 0 };
        this.direction = '';
        this.xVelocity = 1;
        this.yVelocity = 1;
    }

    handleKeyDown({ keyCode }) {
        switch (keyCode) {
            case 87: // 'W' key
                this.direction = 'up';
                break;
            case 65: // 'A' key
                this.direction = 'left';
                break;
            case 83: // 'S' key
                this.direction = 'down';
                break;
            case 68: // 'D' key
                this.direction = 'right';
                break;
        }
    }
}

// Example usage
const gameObject = new GameObject();
console.log('Initial State:', gameObject);

gameObject.handleKeyDown({ keyCode: 87 }); // Simulate 'W' key press
console.log('After W Key Press:', gameObject);

gameObject.handleKeyDown({ keyCode: 65 }); // Simulate 'A' key press
console.log('After A Key Press:', gameObject);

gameObject.handleKeyDown({ keyCode: 83 }); // Simulate 'S' key press
console.log('After S Key Press:', gameObject);

gameObject.handleKeyDown({ keyCode: 68 }); // Simulate 'D' key press
console.log('After D Key Press:', gameObject);

<IPython.core.display.Javascript object>

Popcorn Hacks

On if statement can you think of another variable to add to defaults. If you can’t think of anything add “speed”.

On switch statments can you add conditions for IJKL keys.