learn
is a very special command, because it is used to create your own commands. The command you create can take input and return output. Let us take a look at how a new command is created:
learn circle x [ repeat 36 [ forward x turnleft 10 ] ]The new command is called
circle
. circle
takes one input, a number, to set the size of the circle. circle
returns no output. The circle
command can now be used like a normal command in the rest of the code. See this example:
learn circle X [ repeat 36 [ forward X turnleft 10 ] ] go 30,30 circle 20 go 40,40 circle 50
In the next example, a command with a return value is created.
reset learn multiplyBySelf n [ r = n * 1 r = n * n return r ] i = inputwindow "Please enter a number and press OK" print i + " multiplied by itself is: " + multiplyBySelf iIn this example a new command called
multiplyBySelf
is created. The input of this command is multiplied by itself and then returned, using the return
command. The return
command is the way to output a value from a function you have created.
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