Ruby Array Sort By Date

The ruby sorting operator also called the spaceship operator takes two parameters and returns one of three values.

Ruby array sort by date.

The most basic form of sorting is provided by the ruby sort method which is defined by the enumerable module. In the first form if no arguments are sent the new array will be empty. Now we have tasks sorted first by due date and then by priority. Often we must arrange them ourselves.

Ruby sort arrays use the sort method. 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. Fortunately ruby offers the sort method available on arrays.

It can be customized with blocks for extra power. 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. 0 if the two parameters are. If max min or sort is used the objects in the collection must also implement a meaningful operator as these methods rely on an ordering between members of the collection.

The enumerable mixin provides collection classes with several traversal and searching methods and with the ability to sort. In a previous tutorial i wrote about how to sort an array of ruby objects by one field in the object in today s tutorial i d like to demonstrate how to sort an array of ruby objects by multiple attributes or fields of the class contained by the array. 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.

Sorting a ruby array by two or more class attributes may sound difficult but as a friend of mine likes to say it s not too hard once you. The second form creates a copy of the array passed as a parameter the array is generated by calling to ary on the parameter. Sort by handles multiple parameters by sorting the collection according to the first parameter. Returns a new array.

Learn to use the sort sort. Things do not come sorted. The class must provide a method each which yields successive members of the collection.