When concatenating strings it was always recommended to use String buffer, then later String Builder. I also did the same whenever I needed to. After watching a video by Dr. Venkat Subramaniam now I ...

if(a.length() == 0 && b.length() == 0) return a + b; else if(a.length() == 0) return b; else if(b.length() == 0) return a; else return (a.charAt(a.length() - 1) == b ...