Finding all 3 character length substrings in a string

java, regex

Solution

Implementing Juvanis' idea somewhat, iterate to get your substrings, then use a regular expression to make sure the substring is all letters:

String s = "example string";
for (int i = 0; i <= s.length() - 3; i++) {
    String substr = s.substring(i, i + 3);
    if (substr.matches("[a-zA-Z]+")) { System.out.println(substr); }
}

Problem

I am trying to find all three letter substrings from a string in Java. For example from the string "example string" I should get "exa", "xam", "amp", "mpl", "ple", "str", "tri", "rin", "ing". I tried using the Java Regular expression "([a-zA-Z]){3}" but I only got "exa", "mpl", "str", "ing". Can someone tell me a regex or method to correct this.

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