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notes:perl_cheat_sheet [2013/09/22 19:27]
smthng [Hashes] |
notes:perl_cheat_sheet [2013/09/22 19:28] (current)
smthng [Hashes] |
| * ''%revhash = reverse %hash'' to reverse a hash (for non-unique values, last one wins). | * ''%revhash = reverse %hash'' to reverse a hash (for non-unique values, last one wins). |
| * ''keys %hash;'' and ''values %hash;'' return a list of keys or value in same order (or # of keys/values in scalar context). | * ''keys %hash;'' and ''values %hash;'' return a list of keys or value in same order (or # of keys/values in scalar context). |
| * '' %hash' is true only if hash has at least one key-value pair. | * '' %hash'' is true only if hash has at least one key-value pair. |
| * To iterate over hash : <code perl>while ( ($key, $value) = each %hash ) { | * To iterate over hash : <code perl>while ( ($key, $value) = each %hash ) { |
| print "$key => $value\n"; }</code> or in order of keys <code perl>foreach $key (sort keys %hash) { | print "$key => $value\n"; }</code> or in order of keys <code perl>foreach $key (sort keys %hash) { |
