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CONDITIONAL BLOCKS
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, as they are loop blocks.
LOOPS
All the programs or projects developed till now ran only once. If you want to run a set of
statements more than once, you will either run the code again or write the script again. In
Scratch, we can save our time and effort by repeating the code without writing the program
again or writing the script again. The automatic running of a set of instructions more than once
is called looping. The blocks for looping are given in Control category.
The Repeat() block is used to run a set of instructions for a specified number of repeat 10
times.
The Forever block is used to run a set of instructions continuously until stopped. forever
The instructions inside this block will be executed in a loop until the Stop button
is clicked by the user.
Conditional Blocks in Scratch 133

