Java tutorial
public class Main { public static void main(String[] args) { char a[] = { 'a', 'b', '5', '?', 'A', ' ' }; for (int i = 0; i < a.length; i++) { if (Character.isDigit(a[i])) System.out.println(a[i] + "is a digit "); if (Character.isLetter(a[i])) System.out.println(a[i] + "is a letter "); if (Character.isWhitespace(a[i])) System.out.println(a[i] + "is a White Space "); if (Character.isLowerCase(a[i])) System.out.println(a[i] + "is a lower case "); if (Character.isLowerCase(a[i])) System.out.println(a[i] + "is a upper case "); } } }