java - for loop to convert integer values into letters -

i working on homework assignment encodes , decodes letters int's , vice versa. first encoding loop have works great!

public static string encode(string msg){    string result="";    string m = msg.touppercase();     char c;     int x;      (int = 0; i<m.length(); i++){         c = m.charat(i);         x = c;         if (x == 32){             x = 0;         } else{             x -= 64;             if (x < 1 || x > 26){                 x = 99;             }         }         result += string.valueof(x) + " ";     }      return result; } 

it takes string msg , runs loop convert integer equivalent. issue decoding. essentially, numbers input entered in comma in between each number. take message array , split remove commas. take , read each value in loop , display letter equivalent. stuck. understand logic. it's reverse of first loop, cannot seem code it. here have:

public static string decode(string msg){     string result = "";     string m = msg;     char c;     int x;      string[] nums = msg.split(",");         (int = 0; i<nums.length; i++){      string num = nums[i];     x = integer.parseint(num);     if(x <= 0 || x > 26){            x=-1;        }           result += string.valueof((char)(x + 64)) + " ";     }      return result;  } 

i having issues reading length of nums array. haven't had luck rest of it. understand have parse integers well. insight completing appreciated!

since it's homework, i'll give next step; can figure out there :)

in loop:

string num = nums[i]; x = integer.parseint(num);