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5.1. Adding an Element to a Hash
5.1.1. Problem
You need to add an entry to a
hash.
5.1.2. Solution
Simply assign to the hash key:$HASH{$KEY} = $VALUE;
5.1.3. Discussion
Putting something into a hash is straightforward. In languages that
don't provide the hash as an intrinsic data type, you have to worry
about overflows, resizing, and collisions in your hash table. In
Perl, all that is taken care of for you with a simple assignment. If
that entry was already occupied (had a previous value), memory for
that value is automatically freed, just as when assigning to a simple
scalar.# %food_color defined per the introduction
$food_color{Raspberry} = "pink";
print "Known foods:\n";
foreach $food (keys %food_color) {
print "$food\n";
}
Known foods:
Banana
Apple
Raspberry
Carrot
Lemon
If you don't want to overwrite an existing value, but somehow have
one key reference multiple values, see Recipe 5.8 and Recipe 11.2.
5.1.4. See Also
The "List Value Constructors" section of
perldata(1); the "List Values and Arrays"
section of Chapter 2 of Programming Perl; Recipe 5.2
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| 5. Hashes |  | 5.2. Testing for the Presence of a Key in a Hash |
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