1. Scorrimento laterale dei giochi e affermazioni "Se-altrimenti"

Hey, and Welcome to Scratch Games day 8. Today you’ll create a side-scrolling game while learning about if-else statements. You might be familiar with recent side-scrolling games, like Helicopter and Flappy Bird. You’ll notice that in these games, the sprite only moves up and down. The illusion of moving forward is created by moving the background.

To create today’s game, you’ll also learn about if-else statements.

“If-else” statements are very similar to if statements. Remember, an “if” statement reads like this: An “if ELSE” statement reads like this: “If-else” statements are useful because they let you specify a default action.

Watch how “if-else” statements are used to program video games.

In “Tetris,” the best-selling video game of all time, the user must manipulate falling shapes to arrange them into rows. IF the user presses the down arrow, the falling shapes fall down really fast. ELSE, they fall down at the regular speed. An if-else statement is useful here because the falling shapes need to do one action all the time, but switch to doing another action when something specific happens.

In Plants vs Zombies, the user must defeat waves of zombies using plants with special powers.

IF there is a zombie near the scaredy shroom, it cowers down and doesn’t shoot.

ELSE, it continuously shoots at the zombies. Just like the creators of those popular games, you’ll use if-else statements to build your project today. In this game, a sprite is controlled using an if-else statement. For example, If the space bar is being pressed, then go up.

Else, go down. Before moving on to the next screencast, click and open the starter project link next to this page and add a player sprite. You may want to choose a sprite that looks like it’s flying, like a parrot, bat, or butterfly.

Once you’ve completed this screencast, move on to the next screencast to learn how to create a scrolling background.