Trouble with the bob game in Javascript

I made my way to the Bob game in Javascript. I completed all the steps and I am somewhat confident, that I figured it out. However, the game preview is blank and I can’t play the game at all.

There is no error console, the tips are not specific enough, so I can actually check what I did wrong in the code, and there is no video solution this time. How am I supposed to figure out what is wrong now?

Here is what I got:

// Add a variable to keep count of Bob's earnings let score = 0; // Add a variable to multiply money const moneyMultiplier = 100; // Add a variable to control speed of Bob sprite const speed = 1; // Values used to keep track of where money and paper appear const gameState = { numCoordinates: {}, }; let randomCoord; class GameScene extends Phaser.Scene { constructor() { super({ key: 'GameScene' }); } preload() { this.load.image('bob-front', ''); this.load.image('bob-back', ''); this.load.image('bob-side', ''); this.load.image('money', ''); this.load.image('paper', ''); } create() { // Display text showing how much cash Bob earned let scoreText = this.add.text(140, 610, `Earnings: $${score}`, { fontSize: '25px', fill: '#fff' }); // Create the Bob sprite and set boundaries for it gameState.player = this.physics.add.sprite(240, 500, 'bob-front').setScale(.8);, 0, 480, 600); // Slightly above score gameState.player.setCollideWorldBounds(true); gameState.player.body.collideWorldBounds = true; // Create money sprite in random spots on canvas randomCoord = assignCoords(); = this.physics.add.sprite(randomCoord.x, randomCoord.y, 'money').setScale(.5); // Create paper sprite group gameState.enemies =; // Collision detection between Bob and money sprite this.physics.add.overlap(gameState.player,, () => { // Hide and deactivate the money sprite after Bob collides with it; // Move money somewhere else on the canvas delete gameState.numCoordinates[`x${}y${}`]; randomCoord = assignCoords(); // Place the money sprite somewhere new, then show and activate it, randomCoord.x, randomCoord.y); // Increase the score randomly between 100 and 1000 score += (Math.round(Math.random() * 10) * moneyMultiplier); // Update cash total text scoreText.setText(`Earnings: \$${score}`); // Place paper sprite on canvas randomly randomCoord = assignCoords(); gameState.enemies.create(randomCoord.x, randomCoord.y, 'paper').setScale(.6); }); // Collision detection between Bob and paper sprites this.physics.add.collider(gameState.player, gameState.enemies, () => this.endGame()); // Helper function to return an object containing evenly spaced x and y coordinates: function generateRandomCoords() { const randomX = Math.floor(Math.random() * 5) * 75 + 25 const randomY = Math.floor(Math.random() * 5) * 75 + 25 return { x: randomX, y: randomY } } // Helper function that returns one set of coordinates not in gameState.numCoordinates function assignCoords() { let assignedCoord = generateRandomCoords(); // If the coordinates are already in gameState.numCoordinates, then other set of coordinates are generated until there is one not in use while (gameState.numCoordinates[`x${assignedCoord.x}y${assignedCoord.y}`]) { assignedCoord = generateRandomCoords() } gameState.numCoordinates[`x${assignedCoord.x}y${assignedCoord.y}`] = true return assignedCoord; } } update() { // Arrow keys that will move Bob in 4 directions const cursors = this.input.keyboard.createCursorKeys(); // Add variables that store if a specific arrow key is being pressed const rightArrow = cursors.right.isDown; const leftArrow = cursors.left.isDown; const upArrow = cursors.up.isDown; const downArrow = cursors.down.isDown; // Add code to check whether any of the arrow keys were pressed, move Bob if (rightArrow === true) { moveBobRight(); } else (leftArrow === true) { moveBobLeft(); } else (upArrow === true) { moveBobUp(); } else (downArrow === true) { moveBobDown(); } // Add variables that store the x and y coordinates of the Bob sprite const bobXCoord = gameState.Player.x; const bobYCoord = gameState.Player.y; // Add code to check collision between Bob and edges of the canvas of the game if (bobXCoord <= 32 || bobXCoord >= 448) { this.endgame(); } if (bobYCoord <= 32 || bobYCoord >= 568) { this.endgame(); } // Helper functions to move Bob in 4 directions function moveBobRight() { gameState.player.flipX = false; gameState.player.setTexture('bob-side'); gameState.player.setVelocityX(150 * speed); gameState.player.setVelocityY(0); } function moveBobLeft() { // NOTE: By default Bob looks to the right so we flip the image if moving left gameState.player.flipX = true; gameState.player.setTexture('bob-side'); gameState.player.setVelocityX(-150 * speed); gameState.player.setVelocityY(0); } function moveBobUp() { gameState.player.flipX = false; gameState.player.setTexture('bob-back'); gameState.player.setVelocityX(0); gameState.player.setVelocityY(-150 * speed); } function moveBobDown() { gameState.player.flipX = false; gameState.player.setTexture('bob-front'); gameState.player.setVelocityX(0); gameState.player.setVelocityY(150 * speed); } } // Class function that ends current Game and transitions to End Scene endGame() { // Stop sprites moving this.physics.pause(); // Transition to end scene w/fade this.cameras.main.fade(800, 0, 0, 0, false, function (camera, progress) { if (progress > .5) { this.scene.stop('GameScene'); this.scene.start('EndScene'); } }); } }

I believe being able to just tick the points off without the program checking if I did everything right is pretty inconsequential, since I am not aware where I did a mistake and I can essentially skip the exercise without doing anything. Can you help me out and explain what went wrong here?

Hi, If you look at your if statement from line 99 the else should be else if? i tried it and it fixed that bug. the next bug is from line 15, the Phaser.Scene in not defined. I haven’t come that far into the course so can’t help there but i hope it points you in the right direction.

1 Like

When I change it to else if, then it returns unexpected token “else” so I believe it shouldn’t be else if. I was told to not mind the phaser stuff at all!

@ruby4364770088 was correct. Starting on line 99 (with the if statement), look at the following else statements. Should they be else or else if statements? Does it makes sense to have more than one else block in a logic block or to have a condition after an else?

Ok, I see. If I do that and change the other 3 arrows to else if, then the error code would be:

class GameScene extends Phaser.Scene {

ReferenceError: Phaser is not defined

and it points towards line 15.

The task didn’t intend that I change anything in the already existing phaser code. Also, it didn’t teach anything about phaser itself yet, so I can’t know what is wrong in there.

I’ve been trying to figure this one out. I was looking at Phaser documentation and I’m pretty sure

const cursors = this.input.keyboard.createCursorKeys();

already creates the four cursor objects so trying to make them again is breaking it. When I comment out the const cursor variables I think everything seems to be working fine.