An Intro to Perl, Pt. 2

Hashes, Foreach Control, and the Split Function

Hashes (Associative Arrays)

• Arrays with string indices• Each index is called a key• Different braces than arrays ({} not [])• Use the % sigil to symbolize a hash

Example Hashes

• $numbers{“one”}=”1”; Assigns 1 to key “one”• $numbers{“two”}=”2”; (accessed as a scalar)• $numbers{“three”}=”3”;

• %numbers=(“one”,”1”,”two”,”2”,”three”,”3”);Creates hash with indices one, two, three and

values of 1, 2, and 3

Hash Control

• while(($key, $value) = each %numbers){print "$key $value\n”;}

Prints out individual Key-value pairs for the hash

Foreach Control Statement

• For loop designed for processing arrays, hashes, and lists.

• @word=(“This”, “is”, “an”, “array”);• foreach $word (@words){

print "$word\n";}@myNames = ('Larry', 'Curly', 'Moe');

foreach (@myNames) {print $_ . “\n”;}

The Split Function

• Splits a string using a specific delimiter• @fields=split " ", $string;If $string = “The quick brown fox”@fields= (“The”, “quick”, “brown”, “fox”)• Default delimiter is a space “ “• $info = "Caine:Michael:Actor:14, Leafy Drive";

@personal = split(/:/, $info);