how to remove a digit from a number in java code example

Example 1: how to remove numbers from string java

Extract  numbers from a string

Character.isDigit(str.charAt(i))
Character.isLetter(str.charAt(i))
Character.isAlphabetic(str.charAt(i))

String password = "cnE4g1Z5y9A";	
String[] letters= password.split("[0-9]");    ==> cnEgZyA
String[] letters= password.split("[A-Za-z]");    ==> 4159

Example 2: java eliminate numbers from string

firstname1 = firstname1.replaceAll("[0-9]","");