1768_Merge_Strings_Alternately.java

class Solution {
    public String mergeAlternately(String word1, String word2) {
      StringBuilder sb = new StringBuilder();
      int i = 0 , j = 0 ;
      while(i < word1.length() || j < word2.length()){
          if( i < word1.length()){
            sb.append(word1.charAt(i));
            i++;
          }
          if(j < word2.length()){
            sb.append(word2.charAt(j));
            j++;
          }
      }  
      return sb.toString();
    }
}