comefrom: <awangdev>415. Add Strings_1.java
code: public String addStrings(String num1, String num2) {
           StringBuffer sb = new StringBuffer();
           int carry = 0;
           int i = num1.length() - 1, j = num2.length() - 1;
  
           for (; i >= 0 || j >= 0 || carry == 1; i--, j--) { 
               int x = i < 0 ? 0 : (num1.charAt(i) - '0');
               int y = j < 0 ? 0 : (num2.charAt(j) - '0');
               int sum = x + y + carry;
               sb.append(sum % 10);
               carry = sum / 10;
           }
  
           return sb.reverse().toString();
       }
masked: public String var_0 ( String var_1 , String var_2 ) {
    StringBuffer var_3 = new StringBuffer ( ) ;
    int var_4 = 0 ;
    int var_5 = var_1 . length ( ) - 1 , var_6 = var_2 . length ( ) - 1 ;
    for ( ;
    var_5 >= 0 || var_6 >= 0 || var_4 == 1 ;
    var_5 -- , var_6 -- ) {
      int var_7 = var_5 < 0 ? 0 : ( var_1 . charAt ( var_5 ) - '0' ) ;
      int var_8 = var_6 < 0 ? 0 : ( var_2 . charAt ( var_6 ) - '0' ) ;
      int var_9 = var_7 + var_8 + var_4 ;
      var_3 . append ( var_9 % 10 ) ;
      var_4 = var_9 / 10 ;
    }
    return var_3 . reverse ( ) . toString ( ) ;
  }
  