Shell Programming and Scripting

Some one plz help me how to sort an array of hashes .....

for e.g i have an array as

@AoH = (
{
ques => 10,
marks => 32,
},
{
ques => 32,
marks => 22,
},
{
ques => 2,
marks => 41,
},
);

now i want to sort this array with increasing value of "ques" ..... plz help

If this is Perl, this is an array of hash references. You can't strictly make an array of hashes in Perl, as this will eventually become a single array.

It's actually very simple:

Code:

@sorted = sort { $$a{'ques'} <=> $$b{'ques'} } @AoH;

EDIT: Actually the perldsc manpage has all the details (hopefully it won't overwhelm you!)

one more thing ... wat if i want to put 'ques' 32 and 'ques' 18 together and other 'ques' sorted ...

Perl's sort function is immensely powerful (and somewhat difficult to explain) that lets you sort in any way you desire. Theoretically you can put the condition (the comparator) in the sort {} block to generate a custom ordering for your case. But your question is not precise. And you cannot simply say keep 32 and 18 together, because what should be the ordering of other array items with respect to 32 and 18, respectively? And the order of 32 and 18? If these questions are not defined, the condition in the sort {} block will not be accurate to establish a total ordering, and the sorted results will then be non-deterministic (i.e. simply wrong).

Mathematically speaking, given a total of n items to sort, you need to define all possible permutations of any two items in the block, i.e. n * n, and the ordering should be absolutely consistent. So, if you define a certain item x(i) -> 32 and 32 -> 18, the condition in the block should never, ever, generate the order 18 -> x(i), or any other items preceding x(i).

In general, if a given sort order is not intuitive, and you cannot specify an algorithm to establish the total ordering, I will suggest getting the normally sorted results and manipulate the rest yourself with another array. For this, I guess you should try to do this yourself.