how to split a string into words in arduino?

I had the same problem but found a very straight forward solution using builtin string functions:

String name="apple orange banana";

Serial.println(name);
int x;
int index = 0;
String arr[3];
int i;
for (i=0;i<3;i++){
   index = name.indexOf(' ');
   arr[i] = name.substring(0, index);
   name = name.substring(index+1);
   Serial.println(arr[i]);  
}

After running this code you get this output:

apple orange banana
apple
orange
banana

I hope it helps

How to split a string using a specific delimiter in Arduino? I believe this would help you, you could do a while loop like:

int x;
String words[3];
while(getValue(name, ' ', x) != NULL){
     words[x] = getValue(name, ' ', x);
}

Using this function:

// https://stackoverflow.com/questions/9072320/split-string-into-string-array
String getValue(String data, char separator, int index)
{
  int found = 0;
  int strIndex[] = {0, -1};
  int maxIndex = data.length()-1;

  for(int i=0; i<=maxIndex && found<=index; i++){
    if(data.charAt(i)==separator || i==maxIndex){
        found++;
        strIndex[0] = strIndex[1]+1;
        strIndex[1] = (i == maxIndex) ? i+1 : i;
    }
  }
  return found>index ? data.substring(strIndex[0], strIndex[1]) : "";
}

If you know your list length and the max characters per list item, you could do

char arr[3][6] = {"apple", "orange", banana"};

edit: if you are looking for something like String arr[3] you aren't going to get it because of how memory is managed with the C language