Foreach on a string.

Posted on 1998-07-19
Last Modified: 2010-03-05
Is there anyway to do a foreach loop on a string?  Or a similar loop.  So it loops through once for every char in the string.  So in the word "hello" it would loop 5 times and $k would hold the letter for which it's going through the loop for.
Thanks in Advance.
Question by:cide
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Accepted Solution

alamo earned 10 total points
ID: 1208515
$str ="'hello";
foreach $k (split('',$str)) { print "$k\n"};

This doesn't get you the ability to change the characters in the original string, though, of that's what you want. In that case a simple for loop would do, iterating character by character:

for ($i = 0; $i < length($str); $i++) { print substr($str,$i,1),"\n"; }

LVL 84

Expert Comment

ID: 1208516
for( $str=~/(.)/sg ){ print; }
while( $str=~/(.)/sg ){ print "$1\n"; }
#if you want to change each character:
#if you want the ord of each character:
for( 0..length($str)-1 ){ $k = vec($str,$_,8) }
for( unpack'C*',$str ){print $_,"\n" }

Author Comment

ID: 1208517
Thanks,  I don't actually need to change the string so that works perfectly.  I was origionally doing it the second way you said, but the first way is better.
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Author Comment

ID: 1208518
How would I use split to make it every three characters? I.E.  it would split 1000000 into three elements in an array 1, 000 and 000 and 999999 would split into 999 and 999.
LVL 84

Expert Comment

ID: 1208519
For every three characters, /(...)/sg may be easier than using split
LVL 84

Expert Comment

ID: 1208520
Wait a minute, in your 1,000 example, the dirst element doesn't have three characters.
Perhaps you want "How can I output my numbers with commas added?" from perlfaq5?

Author Comment

ID: 1208521
Sort of but I don't want commas added.  exactly like the comma thing but I don't want commas.  Where the comma should be a new element should start.
LVL 84

Expert Comment

ID: 1208522
How about:
reverse map{''.reverse $_} (reverse($str)=~/(\d{1,3})/g);

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