Ruby Sort_by Method

Introduction to Ruby sort_by Method

A hash or array may be sorted in Ruby using the sort_by method, which is a built-in way for doing so. The key or attribute that will be used to sort the data is defined in a block that this function takes. Depending on the attribute or key that is provided, the sort_by function generates a new array or hash.

Syntax

The sort_by method's syntax is as follows:

Parameters

A block of code containing the attribute or key logic on the basis of which the sorting will occur is passed to the Ruby sort_by function. One or two arguments may be sent to this block.

For array sorting, the block just needs one parameter. Each element of the array is represented by this. The block requires two arguments for sorting a hash. These two parameters stand in for the key and value of each hash-based element.

Return Value

The sort_by function in Ruby creates a new array or hash depending on the sorting criteria specified in the code block and returns it.

Examples

Here are some examples of using the sort_by method:

Sorting an Array

The sort_by method was used in this example to order an array of strings. The length of each word served as the basis for the sorting mechanism. We organized the array so that the shorter words appeared at the start of the array by using the sort_by method along with a block of code that calculates each word's length.

Sorting a Hash

In the example above, we utilized the sort_by method to sort a hash based on its values. By applying the sort_by method to the hash, each key-value pair was compared and arranged in ascending order according to their values.

These examples highlight how the sort_by method can be applied to both arrays and hashes to achieve customized sorting based on specific attributes or keys.

How does sort_by method work?

In Ruby, the sort_by method works by defining the attribute or key that influences data sorting using a block of code. This section of code produces a value for each array element or hash key-value pair, which is then used to compare and sort the items or pairs.

The sort_by method iterates through each element of an array, giving it to the block. Within the block, a value is returned based on the supplied property or key, allowing for element comparison. The array is then organized using the sort_by function depending on the values returned by the block.

Similarly, when sorting a hash, the sort_by method takes into account each key-value pair. It sends each pair to the block, where a value is created depending on the provided attribute or key. This value is used to compare and order the key-value pairs within the hash.

Sorting with Ruby sort_by

Elements may be sorted in Ruby using the sort_by function according to various keys or properties. Some of the applications of the sort_by method are discussed below:

Sort in Reverse Order

We can use the - operator together with the attribute or key to sort an array or hash in the opposite direction. Here's an illustration:

In the example above, the length of each word is utilised to sort the words array in reverse order using the sort_by function.

Alphanumeric Sorting

Sorting data in alphanumeric order is also possible with the sort_by function. Here's an illustration:

The sort_by method is used in the above example to sort the string array in alphanumeric order depending on the integer value present in each string.

This will not function with the standard sort approach. Let's look at the same example using the sort approach.

The result in the above example is undesirable, and it is achieved by simply comparing the values of the several strings.

Sorting Hashes

The sort_by function may be used to arrange hashes based on their keys or values. Here are some examples:

The hash in the above example is sorted using the sort_by method according to its keys and values. The hash is organised in ascending order by its values in the second example and alphabetically by its keys in the first.

Sorting By Multiple Values

The sort_by function may also be used to sort data based on several characteristics or keys. Here's an example:

The sort_by function is used in the above example to sort the persons array depending on numerous properties, including age, team, and name. The sort_by function sorts the array in ascending order depending on the first attribute, then the second attribute, and so on until there's no tie or all conditions has been checked.

Difference Between sort and sort_by Methods in Ruby

The sort and sort_by methods in Ruby serve the purpose of sorting arrays and hashes, but they have some notable differences.

The sort method sorts elements based on their values, taking into account their natural ordering. It arranges the elements in ascending order by default.

On the other hand, the sort_by method allows for more customized sorting. It takes a block of code that determines the sorting logic. The block returns a value that is used for comparison, providing flexibility in sorting based on specific attributes or keys.

Let's explore these differences with examples:

In this example, the sort method is used to sort an array of integers. It arranges the numbers in ascending order based on their values.

In this example, we have used the last character of the string to sort the string array. Since the last character of "scaler", i.e, "r" is the smallest, it comes at first. It is followed by "interviewbit" and lastly "academy" as "t" comes before "y".