Question

I want to take a String str and an int wSize and use it to create a hashtable. An example is the best way to explain what I want.

For example:
str = “alphabet”
wSize = 2

I want a hashtable that looks like this:
al 0
lp 1
ph 2
ha 3
ab 4
be 5
et 6

This is what I have so far

public static void hashTableCreator (String str, int wSize) {
    Hashtable ht = new Hashtable();
    str = "alphabet";
    wSize = 2;
    String str2;

    for (int i = 0; i < str.length(); i++) {
      int value = 0;
      ht.put(str.substring(i, i + 1), value);
      value++;
    }

    Set set = ht.keySet(); 

    Iterator itr = set.iterator();
    while(itr.hasNext()) {
      str2 = (String) itr.next();
      System.out.println(str2 + ": " +
                         ht.get(str2));
    }

  }

Answer 1

in string.substring(a,b) first argument is zero indexed and 2nd argument is 1 indexed.
for example:

      "smiles".substring(1, 5) returns "mile"

if you wanna get al from the string “alphabet” you’d have to do

         LinkedHashMap<String, Integer> ht = new LinkedHashMap<String, Integer>();
 int value=0;
     for(int i=0; i<str.length()-1; i++) {
         ht.put(str.substring(i, i+2), value);
         value++;
     }
     Set<String> set = ht.keySet();
     Iterator<String> itr = set.iterator();
     while(itr.hasNext()) {
         String d = itr.next();
         System.out.println(d+ " "+ ht.get(d));
     }
    }

OUTPUT: al 0
lp 1
ph 2
ha 3
ab 4
be 5
et 6