View source for C Block

[[File:C block grey.svg|thumb|130px|The general shape of a '''C block''']]
A '''C block''' is a [[Blocks|block]] that is shaped like the letter "C" so other blocks can fit inside it. These blocks perform the [[Boolean Block|conditions]] and loops.

== Shape ==
C blocks have a "mouth" (it looks like the letter "C", hence the name) {{-}} the blocks that will be placed inside the C block go in these mouths. All but one of the C blocks consist of one mouth {{-}} the other, [[If () Then, Else (block)|if <> then, else]], consists of two mouths. (For this reason, this block is occasionally referred to as an "E block".<ref>[[post:4717912]]</ref><ref>[[post:380075]]</ref>) When any of the other C blocks are dragged over a stack of blocks {{-}} if the C is empty {{-}} its mouth extends to wrap around them.

<scratchblocks>repeat (10)
repeat until <(loudness) > [30]>
glide (1) secs to x: (10) y: (0)
wait (1) secs
go to x: (0) y: (0)
end
play sound (meow v) until done
end</scratchblocks>

In [[Scratch 1.2]] and earlier, C-block scripts could only be built one block at a time.

Most C blocks, like [[Stack Blocks]], have a notch on the top of the block and a bump on the bottom, signifying that other blocks can be stacked above or below them. The [[Forever (block)|<sb>forever</sb>]] block is an exception in that it only has a notch, as if blocks could be placed under it, they would never run.

== C Blocks in Scratch 3.0 ==
In [[Scratch 3.0]], there are five C blocks, and they can all be found in the [[Control Blocks|Control]] category.
{{note|Click on a block for more information.}}

* [[Repeat () (block)|<sb>repeat ()</sb>]]
* [[Forever (block)|<sb>forever</sb>]] {{-}} this block is also a [[Cap Block]].
* [[If () Then (block)|<sb>if <> then</sb>]]
* [[If () Then, Else (block)|<scratchblocks>if <> then
else</scratchblocks>]]
* [[Repeat Until () (block)|<sb>repeat until <></sb>]]

== Removed C Blocks ==
{{obsolete feature|cat=no}}
{{Block Frame|blocks=
<scratchblocks>forever if <> {
} :: control cap</scratchblocks>
|caption=The Forever If () block.
}}

In [[Scratch 1.4]] and earlier, the [[Forever If ()|<sb>forever if <>::control</sb>]] block could be used. This can be recreated with this workaround:
<scratchblocks>
forever
if <> then
end
end
</scratchblocks>

== Uses ==
As C blocks are for checks and loops, they are used in many places. Some uses include:
* Creating a scripts which runs forever

<scratchblocks>when gf clicked
forever
turn cw (15) degrees</scratchblocks>

* Checking a condition

<scratchblocks>when [space v] key pressed
if <(loudness) > [30]> then
stop [all v]
end</scratchblocks>

* Repeating an animation a certain amount of times

<scratchblocks>when gf clicked
repeat (200)
turn ccw (36) degrees
change [color v] effect by (1)
end</scratchblocks>

Here is an example for both checks and looping:

<scratchblocks>
when I receive [Decrease health v]
change [Health v] by (-1)
if <(health) = [0]> then
repeat (8)
change [color v] effect by (25)
end
end
</scratchblocks>

There is a check (the {{b|If () Then}} block is checking if the [[variable]] ''Health'' has a value of 0), and inside the check is a repeat loop (with the {{b|Repeat ()}} block). Note how C blocks can be placed inside other C blocks.

==References==
<references/>

{{Block Shapes}}
[[Category:Block Shapes]][[Category:C Blocks| ]]
[[de:Blockform = Klammer-Blöcke]]
[[ja:C型ブロック]]