I have strings like these in an Array:
let arr = ["UserA | 3", "UserB | 0", "UserC | 2", "UserD | 1"]
Names and their ID's at the end. I'd like to sort it based on their id's at the end, but couldn't come up with a way to do it.
Add a comment
|
2 Answers
You can do this using String#split and Array#sort, defining a custom compareFunction function in this scheme:
MDN Web Docs:
- If
compareFunction(a, b)returns a value > than 0, sort b before a.- If
compareFunction(a, b)returns a value < than 0, sort a before b.- If
compareFunction(a, b)returns 0, a and b are considered equal.
Like this:
let arr = ["UserA | 3", "UserB | 0", "UserC | 2", "UserD | 1", "UserE | 2020"];
arr.sort((a, b) => a.split(" | ")[1] - b.split(" | ")[1]);
console.log(arr);
Comments
You can create a function to extract the last number id using a RegExp combined with String.prototype.match():
Regular expression: /\d+(?=\D*$)/
- \d matches a digit (equivalent to [0-9])
- + matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
- Positive Lookahead (?=\D*$) Assert that the Regex below matches \D matches any character that's not a digit (equivalent to [^0-9])
- * matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
- $ asserts position at the end of the string, or before the line terminator right at the end of the string (if any)
And finally use Array.prototype.sort()
Code:
const arr = ["UserE | 2020", "UserA | 3", "UserB | 0", "UserC | 2", "UserD | 1"]
const getId = s => +s.match(/\d+(?=\D*$)/)[0]
arr.sort((a, b) => getId(a) - getId(b))
console.log(arr)
1 Comment
Apollo24
Thanks Yosvel, it works perfectly now. If you don't mind, could you explain what each of those elements in the regex do? I don't know much about them. Or do you know a source where I could look them up?