User manual

RP6 ROBOT SYSTEM - 4. Programming the RP6

z++; // abbreviation for z = z + 1; which implies z is now 9

z++; // z = 10 // z++ is called “incrementing z”

z++; // z = 11 ...

z--; // z = 10 // z-- is called “decrementing z”

z--; // z = 9

z--; // z = 8 ...

We previously used the data type “char”. However in most cases we prefer standard

data types in all RP6 programs.

As an example, this: int8_t x;

is identical to: signed char x;

And this: uint8_t x;

is identical to: unsigned char x; // respectively for us this is also true for

“char” only as our char is by default a signed one because of an compiler op-

tion.

4.4.5. Conditional statements

Conditional statements using “if-else”-constructs play an important role in program

flow. They allow us to check whether a condition is true or false and decide if a specif-

ic program part is executed or not.

A small example:

uint8_t x = 10;

if(x == 10)

{

writeString("x is equal to 10!\n");

}

The declaration in line 1 defines an 8-Bit variable x and assigns the value 10 to it. The

succeeding if-condition in line 2 checks, whether the value of x is equal to 10. Obvi-

ously, this condition will always be true and the program will execute the succeeding

block. It will output “x is equal to 10!”. If we would initialize x with a value of 231 in-

stead, the program would not output anything!

Generally, an if-condition will always have the following syntax:

if ( <condition X> )

else

Using plain English language we may also read: “If X then do Y else do Z”.

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