package string.codes; public class IsSubstring { public static boolean isSubtring(String pat, String txt) { int pattern_len = pat.length(); int text_len = txt.length(); for (int i = 0; i <= text_len - pattern_len; i++) { int j; for (j = 0; j < pattern_len; j++) { if (txt.charAt(i+j) != pat.charAt(j)) break; } if (j == pattern_len) { return true; } } return false; } public static void main(String[] args) { String txt = "abcdefghijklmnopqrstuvwxyz"; String pat = "fghij"; System.out.println(isSubtring(pat, txt)); } }