I recently practice a coding challenge and algorithm. Sorting arrays and strings are a bit different. Once you understand the logic, it is not difficult but I thought it was good to organize my thoughts about how sort() works so I want to leave a note here.
Array:
*sort array of numbers
const numberArray = [-1, 14, 2, -3, 9]
numberArray.sort((a, b) => a - b)
#result => [-3, -1, 2, 9, 14]
The opposite order:
numberArray.sort((a, b) => b - a )
#result => [14, 9, 2, -1, -3]
That is also same as:
numberArray.sort(function(a, b) {
return a - b
})
*sort array of strings
Array of strings are just as same as numbers above.
const stringArray = ["coffee", "apple", "pineapple"]
stringArray.sort((a, b) => a - b)
#result => ["apple", "coffee", "pineapple"]
*sort array of strings (unique characters)
But there is an exception. We need localeCompare() for unique characters. Without this function, it can’t be sorted.
const specialStringArray = ['réservé', 'premier', 'cliché', 'communiqué', 'café', 'adieu']
specialStringArray.sort((a, b) => a.localeCompare(b))
#result => [ 'adieu', 'café', 'cliché', 'communiqué', 'premier', 'réservé']
String
How about a string? Remember, sort() is function for Array. So we need to convert a string to an array and get it back to a string agin after sorted.
*sort strings
const string = "pomegranate"
string.split("").sort().join("")
#result => “aaeeegmnoprt”
The other order:
string.split("").sort().reverse().join("")
#result => “trponmgeeeaa”
*sort numbers
We need one more step for the number. Let’s change it to a string first. The rest is the same as the above.
const number = 4356612
const newNumber = number.toString().split("").sort().join("")
parseInt(newNumber)
#result => 1234566
Or one line:
parseInt(number.toString().split("").sort().join(""))
#result => 1234566
Sort is a basic function in JavaScript. However it is a bit tricky to understand how it works for numbers and strings. The function itself is for Array so that we can use it for a string by changing a string to an array - split("").