Ruby Array Sort By Date Desc

Sort by handles multiple parameters by sorting the collection according to the first parameter.

Ruby array sort by date desc.

Just to clarify i m not sure what you mean by adding secondary key sort order key word being secondary. Understanding ruby s built in sorting methods. Being a high level language you won t be implementing sorting algorithms in ruby if you care about performance and besides sorting arrays and other collections are yet more things ruby does. User system total real sort 1 340000 0 010000 1 350000 1 346331 sort reverse 1 300000 0 000000 1 300000 1 310446 sort by a bar 0 430000 0 000000 0 430000 0 429606 sort by a bar 1 0 420000 0 000000 0 420000 0 414383 sort by reverse.

Sorting was a preoccupation for computer scientists from early on. Sort with blocks sort in descending order and sort in place. Please note that these results are different in ruby 1 9. Array sortby function o return new date o date.

Now we have tasks sorted first by due date and then by priority. User system total real sort 0 180000 0 000000 0 180000 0 175469 sort by 1 980000 0 040000 2 020000 2 013586 however consider the case where comparing the keys is a non trivial operation. Please note that these results are different in ruby 1 9. Second adding secondary key sort order to sort by.

Returns a new array. You don t need to write any fancy algorithms to get the result you want. Here are results for ruby 1 9 3p194 2012 04 20 revision 35410 x86 64 darwin10 8 0. Meaning that you first sort by date for example but because you have multiple things with the same date then you have a tie.

There were many algorithms that came into and fell out of use and still today new algorithms are pushing the boundaries of performance. The second form creates a copy of the array passed as a parameter the array is generated by calling to ary on the parameter. You can also use this to sort by multiple criteria if you return an array of values. Ruby program that uses descending sort order contains six different numbers.

Here are results for ruby 1 9 3p194 2012 04 20 revision 35410 x86 64 darwin10 8 0. If your date is not directly comparable make a comparable date out of it e g. When a size and an optional default are sent an array is created with size copies of default take notice that all elements will reference the same object default. In the first form if no arguments are sent the new array will be empty.

I think it may be useful for some cases but it s only slightly better than sort by reverse. Sorting an array in ruby is easy. The following code sorts some files on modification time using the basic sort method. If there are any ties in this case multiple tasks due on monday 5 4 it will fall back to the next parameter given in our case priority.

Array sortby function o return o date. Ruby sort arrays use the sort method.