char + String giving strange result

Issue

Question:
Given a string, take the first 2 chars and return the string with the 2 chars added at both the front and back, so "kitten" yields"kikittenki". If the string length is less than 2, use whatever chars are there.

    front22("kitten") → "kikittenki"
    front22("Ha") → "HaHaHa"
    front22("abc") → "ababcab"

My answer:

public String front22(String str) {
    if(str.length() > 2) {
        char first = str.charAt(0);
        char second = str.charAt(1);
       return first + second + str + first + second;
    }  
    return str + str + str;
}

    Results:
    Expected                           Run             results
    front22("kitten") → "kikittenki"   "212kittenki"   X        
    front22("Ha") → "HaHaHa"           "HaHaHa"        OK       
    front22("abc") → "ababcab"         "195abcab"      X        
    front22("ab") → "ababab"           "ababab"        OK       
    front22("a") → "aaa"               "aaa"           OK       
    front22("") → ""                   ""              OK       
    front22("Logic") → "LoLogicLo"     "187LogicLo"    X        

So where are the numbers i.e. 212, 195 and 187 that are in front of my output are coming from? I am new to JAVA. Sorry if this is something very simple or basic that I don't know.I know I could have done it the following way, but just want to know what's going on with my first answer.

public String front22(String str) {
    if(str.length() > 2){
    return str.substring(0,2) + str + str.substring(0,2);
}

  return str + str + str;
}

Solution

That's the ascii sum of the characters:
For your first case, i has ascii 105 and k has ascii 107 so their sum is 212.
Try str.subString(0, 2) instead of adding the char variables.

Answered By - Ra1nWarden