Hi Monks,

I have some doubts related to file operations and hash of arrays which are as follows:

1. I would like to know that how will I do the translation/ substitution operation on the data stored in Hash of Array data structures.

2. If I have a file 4 columns where the first column act as the id (which can be repeated) and the other three columns are the integer values. 

DATA:
id   col1   col2    col3
12   100    12        196        
12   120    15        190
13   90     190        200
13   70       20       20 
13   101    340        25 
14   100    123        19 
15   80     389        39

[download]

I have read the entire data in a file into Hash of Array. I would like to know how can I do the sum of the rows without taking the the values of the same id present in other columns of the file. My output should look like : 

Output:
id     Sum
12    308
12    325
13    480
13    110
13    466
14    242
15    508

[download]

3. Is their any faster option to delete any column of the file without reading it line by line and then deleting the column using splice function or shift (for deleting the first column) etc.

In reply to Hash of Arrays and File Operations by snape

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