I read as far as your premise. It's wrong. To test if a scalar has been set use:

if (defined $scalar) {

[download]

To test if a hash key/value pair exists use:

if (exists $hash{key}) {

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To test if the scalar content of a hash value has been set use:

if (defined $hash{key}) {

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Those last two steps can be combined:

if (exists $hash{key} && defined $hash{key}) {

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and of course you can make the same tests with a multi-dimensional hash:

if (exists $hash{key1}{key2} && defined $hash{key1}{key2}) {

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This last example is interesting if key1 didn't exist - it pops into existence. This is a process called autovivification and happens when Perl needs to have a hash or array element in order to write to it or use it to access an element is references.

True laziness is hard work

In reply to Re: Best Multidimensional Hash Practices? by GrandFather
in thread Best Multidimensional Hash Practices? by DamianKaelGreen

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