setWord and a complicated (for me) string.

#1 Original String
%originalString = "How Now Brown Cow"

0 How
1 Now
2 Brown
3 Cow

New Word
%newWord = "Chicken"


Syntax
setWord(string to search, # of which word to set, replacement word)
Returns new string

Example

%newString = setWord(%originalString, 3, %newWord);

New String Value
"How Now Brown Chicken"

#2 I apologise, I was looking at this line

%growAnim = setWord(%growAnim, %j, getWord(%this.dieAnim.animationFrames, %i));

like it had 4 variables, not three.

my apology.

thanks.

#3 There are only 3 variables, but it might make more sense to run through the entire example:

%this.dieAnim = %this.owner.getAnimation();
%j = 0;
for (%i = getWordCount(%this.dieAnim.animationFrames) - 1; %i >= 0; %i--)
{
  %growAnim = setWord(%growAnim, %j, getWord(%this.dieAnim.animationFrames, %i));
  %j++;
}

So the user has created an animation to represent dying and has assigned it to an object. Then then put the "PlantGrowthBehavior" on the same object.

There are several variables, which I will estimate definitions for:
%this.dieAnim - An animation which make the plant look like it is dying. %this.dieAnim.animationFrames will contain a string which represents the sequence of frames which make the plant look like it is dying.
%growAnim - The string which represents the sequence of frames which make the plant look like it is growing.
%j - The location in the %growAnim string that we want to replace.
%i - The location in the %this.dieAnim string that we want to look at.


After the first line

%this.dieAnim = %this.owner.getAnimation();

the variable "%this.dieAnim" will contain the animation made for death. The variable "%this.dieAnim.animationFrames" may contain a string which looks like the following (without the quotes):

"1 3 5"

Next, we want to build a new string that reverses these numbers.

On the next line

%j = 0;

we've set up a "%j" to be 0. "%j" represents the location in the "%growAnim" that we want to replace.

The next lines should be taken together

for (%i = getWordCount(%this.dieAnim.animationFrames) - 1; %i >= 0; %i--)
{
  %growAnim = setWord(%growAnim, %j, getWord(%this.dieAnim.animationFrames, %i));
  %j++;
}

First, the engine will call

getWordCount(%this.dieAnim.animationFrames) - 1

which gets translated to (in my example)

getWordCount( "1 3 5" ) - 1

As there are 3 words in "%this.dieAnim.animationFrames", this piece of code will return the number "2".

In essense, the code now looks like

for (%i = 2; %i >= 0; %i--)
{
  %growAnim = setWord(%growAnim, %j, getWord(%this.dieAnim.animationFrames, %i));
  %j++;
}

The first time through the for-loop, "%i" will equal 2, meaning we want to look at word "2" in the string. So the inside of the for-loop looks like this

%growAnim = setWord( %growAnim, 0, getWord( "1 3 5", 2 ) );
%j++;

The variable "%growAnim" has not been used before, therefore it will be assigned the value "" (known as the empty string). Substituting again, we get

%growAnim = setWord( "", 0, "5" );
%j++;

It looks silly, but the code can handle this. There are no words yet, but if you set word 0 to the string "5", you'd get the string "5". Now we have

%growAnim = "5";
%j++;

The final "%j++" will turn "%j" from "0" to "1".

Now, again, through the for-loop, we first call "%i--", turning "%i" from "2" to "1". We then check "%i >= 0", which is true, so we go again through the for-loop.

%growAnim = setWord( %growAnim, 1, getWord( "1 3 5", 1 ) );
%j++;

// Turns into...
%growAnim = setWord( "5", 1, "3" );
%j++;

// Turns into...
%growAnim = "5 3";
%j++;

The final "%j++" will turn "%j" from "1" to "2".

Now, again, through the for-loop, we first call "%i--", turning "%i" from "1" to "0". We then check "%i >= 0", which is true, so we go again through the for-loop.

%growAnim = setWord( %growAnim, 2, getWord( "1 3 5", 0 ) );
%j++;

// Turns into...
%growAnim = setWord( "5 3", 2, "1" );
%j++;

// Turns into...
%growAnim = "5 3 1";
%j++;

The final "%j++" will turn "%j" from "2" to "3".

Now, again, through the for-loop, we first call "%i--", turning "%i" from "0" to "-1". We then check "%i >= 0", which is false, so we stop!

Now we've turned the string "5 3 1" into a new string with "1 3 5"!