Write a line of code to move a sprite across a terrain in all four directions, and write it in Javascript

Answer 1

sprite.x += speed; //move right
sprite.x -= speed; //move left
sprite.y += speed; //move down
sprite.y -= speed; //move up

Answer 2

Write a line of code to move a sprite across a platform in all four directions, be able to attack, and write it in Javascript

Answer 3

Assuming the platform is a solid surface with collision detection:

//move right
if (rightPressed && sprite.x < canvas.width - sprite.width) {
sprite.x += speed;
}

//move left
if (leftPressed && sprite.x > 0) {
sprite.x -= speed;
}

//jump
if (spacePressed && sprite.jumping == false && sprite.grounded == true) {
sprite.jumping = true;
sprite.grounded = false;
sprite.y_velocity = -sprite.jumpStrength;
}

//attack
if (attackPressed) {
//insert attack animation code here
}

This code assumes you have defined the variables "rightPressed", "leftPressed", "spacePressed", and "attackPressed" to detect user input, and "speed" and "jumpStrength" to control how far and how high the sprite can move, respectively. You'll also need to define variables to keep track of whether the sprite is jumping and whether it's on the ground (which can be updated through collision detection with the platform). The attack code will depend on the specifics of your game, but this should give you a general template to work with.