You're absolutely right. I copied-pasted the code from bioperl.org onto this post without checking to see if it was wrong. When I used it in my terminal, I typed it all out and automatically changed the $ sign in $alphabet to an @, which is why it worked fine for me. And I agree, I should have gone for @bases directly instead of using that extra array which is not used anywhere else in the code. I will pay more attention to these details next time I code something up, so thanks for the tip!
On another note, I'd like to go back to my original question. I now understand that this foreach loop is being used to repeat its code (k-1) times. Let's assume $k = 3.
When $_ = 1 (first iteration of the foreach loop), we make the strings (AA, AT, AG... CC) and push them all into @newwords.
When $_ = 2, if we repeated the code inside the loop, we should produce another set of (AA...CC) and push them into @newwords, which is reinitialised in this second iteration through the loop.
I know this is not the case, however, because if I add the following code:
after this line:
push (@newwords, $w.$b);we can see that we are now pushing (AAA...CCC) to the @newwords array, despite the code being exactly the same as in the first iteration.
This is exactly what I want my code to do, although I don't understand why it is working. We are pushing 3-character strings, although according to this code, we are only pushing strings of two characters ($w.$b) into the @newwords array.
In reply to Re^4: How do foreach loops use their list values?
by enderk
in thread [Solved]How do foreach loops use their list values?
by enderk
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