\b;Exercise
Destroy the six \l;targets\u object\bottarg; with a program using a loop. The bot must move 5m forward to get from one target to the next.

\b;General principle
The program must execute the following scheme:
Repeat 6 times :
	o  move 5m forward
	o  turn 90 degrees left
	o  shoot
	o  turn 90 degrees right

\image tfor1 14 5;
\b;Instruction \c;for ( )\n;
The instruction \c;\l;for\u cbot\for;\n; asks for 3 expressions:
1) Initialize the counting variable.
2) The end \l;condition\u cbot\cond;.
3) The counting \l;expression\u cbot\expr;.

Here is the loop once it is integrated into the program frame:
\s;\c;extern void object::Massacre( )
\s;{
\s;	for ( int i=0 ; i<6 ; i=i+1 )
\s;	{
\s;		\n;instructions repeated 6 times ...\c;
\s;	}
\s;}
\n;
ATTENTION: The line \c;for ( )\n; must not be followed by a \l;semicolon\u cbot\term; !

\b;Explanation of the instruction \c;for ( )\n;
1) \c;int i=0\n;
    The \l;variable\u cbot\var; i is set to zero before the beginning of the loop.

2) \c;i<6\n;
    The loop will be executed as long as i is smaller than 6.

3) \c;i=i+1\n;
    At the end of every loop, add 1 to the variable i.

\b;Blocks
Use braces \c;{ }\n; in order to create a \l;block\u cbot\bloc;. All the instructions that must be executed in the \c;for\n; loop are held together by a block. The whole program itself is made up of a block:
\c;
\s;extern void object::massacre( )
\s;{
\s;	\n;fill in here ...\c;
\s;}
\n;
Never change these characters. Just add the instructions of the program between the braces.
You can fit several blocks one into the other. For example the \c;for\n; block is fitted into the block of the whole program. In order to improve readability, the editor lines up the braces belonging to the different blocks.

\b;Remember
The instruction used to move forward is \c;\l;move\u cbot\move;();\n;.
The instruction used to turn the bot is \c;\l;turn\u cbot\turn;();\n;. A positive angle turns left.
The instruction used to fire the cannon is \c;\l;fire\u cbot\fire;(1);\n;. A one-second burst allows to destroy all six \l;targets\u object\bottarg;.

\t;See also
\l;Programming\u cbot;, \l;types\u cbot\type; and \l;categories\u cbot\category;.
