Slugify a String

Easy Real-World Scenarios

Turn a title into a URL-friendly slug: lowercase, replace runs of non-alphanumeric characters with hyphens, and trim stray hyphens.

Sample input

Hello World! This is Test

Sample output

hello-world-this-is-test

Solution

import re

s = "Hello World! This is Test"
slug = re.sub(r"[^a-z0-9]+", "-", s.lower()).strip("-")
print(slug)

const s = "Hello World! This is Test";
const slug = s.toLowerCase().replace(/[^a-z0-9]+/g, "-").replace(/^-+|-+$/g, "");
console.log(slug);

public class Main {
    public static void main(String[] args) {
        String s = "Hello World! This is Test";
        String slug = s.toLowerCase().replaceAll("[^a-z0-9]+", "-").replaceAll("^-+|-+$", "");
        System.out.println(slug);
    }
}

fun main() {
    val s = "Hello World! This is Test"
    val slug = s.lowercase()
        .replace(Regex("[^a-z0-9]+"), "-")
        .trim('-')
    println(slug)
}

import Foundation

let s = "Hello World! This is Test"
let slug = s.lowercased()
    .replacingOccurrences(of: "[^a-z0-9]+", with: "-", options: .regularExpression)
    .trimmingCharacters(in: CharacterSet(charactersIn: "-"))
print(slug)

void main() {
  final s = "Hello World! This is Test";
  final slug = s
      .toLowerCase()
      .replaceAll(RegExp(r'[^a-z0-9]+'), '-')
      .replaceAll(RegExp(r'^-+|-+$'), '');
  print(slug);
}

#include <iostream>
#include <string>
#include <cctype>
using namespace std;

int main() {
    string s = "Hello World! This is Test";
    string slug;
    bool prevHyphen = false;
    for (char c : s) {
        if (isalnum((unsigned char) c)) {
            slug += tolower(c);
            prevHyphen = false;
        } else if (!prevHyphen && !slug.empty()) {
            slug += '-';
            prevHyphen = true;
        }
    }
    while (!slug.empty() && slug.back() == '-') slug.pop_back();
    cout << slug << endl;
    return 0;
}

#include <stdio.h>
#include <ctype.h>

int main() {
    char s[] = "Hello World! This is Test";
    char slug[100];
    int idx = 0, prevHyphen = 0;
    for (int i = 0; s[i]; i++) {
        if (isalnum((unsigned char) s[i])) {
            slug[idx++] = tolower(s[i]);
            prevHyphen = 0;
        } else if (!prevHyphen && idx > 0) {
            slug[idx++] = '-';
            prevHyphen = 1;
        }
    }
    while (idx > 0 && slug[idx - 1] == '-') idx--;
    slug[idx] = '\0';
    printf("%s\n", slug);
    return 0;
}