Page 66 - 2617_JSSPS_C-4

CONDITIONAL STATEMENTS

Many times, you have to do a task which is dependent on some condition. For example, you
have to make mango shake. There are two conditions:

a. Go to the refrigerator and check if there are mangoes. If mangoes are there, then you will
make mango shake.

b. If mangoes are not there, you will make cold coffee.

Here the condition is the availability of mango.
We can also write this in two ways:
1. if 2. if
mango is available mango is available

then then
make the mango shake make the mango shake
else

make cold coffee

In such situations, we use conditional blocks. Scratch has two conditional blocks. They are:

If,then block: In this block if the condition is true, the blocks inside conditional block will
run. If the condition is false, the blocks inside conditional block will not run. Only the blocks
outside the conditional block will run.

If,then,..else block: In this block if the condition is true, the blocks
inside then condition will run. If the condition is false, the blocks
inside else condition will run.

You can also use the forever and repeat blocks with these blocks.
Let us make a small script.
Change the sprite to butterfly and change the backdrop to flowers.

Drag the Event block, when Green Flag clicked to the script area.
Drag the control block, forever to the script area and put it to the
Green Flag block. Drag the move block and put it inside the forever
block. Now, drag the if on edge, bounce block and put it inside the
forever block.

Now, put the control block if, then inside the
forever block and snap the sensing block,
touching color in the hexagon of the if loop.

The butterfly changes colour and size when
it touches the colours selected in the touch
block.

Similarly, you can create scripts with two sprites and they change
colour when they touch each other.

Premium Edition-IV
64