Split/Unsplit in Java/Scala

Scratch.java

import java.util.Arrays;

class Scratch {
    public static void main(String[] args) {
         System.out.println(Arrays.equals("a".split("b"),("ab".split("b")))); //true
        
        // but 
        System.out.println("a".equals(unsplit("a".split("b",-1),"b"))); // true
        System.out.println("ab".equals(unsplit("ab".split("b",-1),"b"))); // true

    }

    public static String unsplit(String[] args,String splitter) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0;i < args.length-1; i++) {
            sb.append(args[i]);
            sb.append(splitter);
        }
        sb.append(args[args.length-1]);
        return sb.toString();
    }
}

Scratch.scala

"ab".equals("ab".split("b",-1).mkString("b")) // true
"a".equals("a".split("b",-1).mkString("b")) // true

Thanks for making this! I found it first and it was going to solve my problem.

For future readers, you can also consider the Java 8 String.join(), as I just found out.

Indeed using String.join() is the best option, I don't remember why I did such function
(Maybe the project was in Java 7, join was introduced in Java 8 )