(upbeat music)
Hey, and welcome to scratch games day eight.
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.
If a condition is true, do this action, or else, do nothing.
An if else statement reads like this.
If a condition is true, do this action,
or else, do this action instead.
If else statements are useful,
because it lets you specify a default action.
Watch how if else statements are used
to program video games.
In Tetris, the bestselling 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 scary 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.
Once you've completed the screencast,
move on to the screencast to learn
how to create a scrolling background.
