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Topic: declaring relative to height. (Read 599 times) |
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benelek
 
 
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declaring relative to height.
« on: Jan 8th, 2003, 1:25pm » |
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ok, so this's my lack of knowledge about the order of compilation, but here's a question: how come, when i declare a variable, say, outside of a procedure, and i define it relative to height, the height is given as 0.
for example:
Code:
void setup() {
size(200,200);
}
int a = width;
int b = height;
void loop() {
println(a + ', ' + b);
}
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this code will print out the line "0, 0" in proce55ing. obviously the variables a and b have been declared by the time loop() is called, otherwise an error would be given. and aren't all variables created only after the size() is given?
is there a magic veil hanging between the workings of proce55ing and my eyes?
is this a bug?
should i go to bed? (yes)
-jacob
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fry
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Re: declaring relative to height.
« Reply #1 on: Jan 8th, 2003, 2:39pm » |
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variables declared outside a function that have definitions, eg. a = width, or a = 3, will be defined when the class is created. this means that before anything is run, the variable is set.
so in this case, by the time setup() is called, a and b are already set to 'width' and 'height', which have no value set for them.
why not just use width and height?
you're right, size() sets all the graphics-oriented variables, but because a and b are being assigned to the current value of width/height at startup, they just wind up being zero.
(note that this isn't just a p5 thing, it's built into java and c++ and most other languages as such..)
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| « Last Edit: Jan 8th, 2003, 2:40pm by fry » |
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