2
9
String str = "abcd123546fde"; str = str.replaceAll("[^0-9]","");
String out = ""; String str = "abcd123546fde"; for (char i : str.toCharArray()) { if ((i >= 'a' && i <= 'z') || (i >= 'A' && i <= 'Z')) { continue; } out += i + ""; } System.out.println(out);