Java Comparable interface. It provides a single sorting sequence only, i.e., you can sort the elements on the basis of single data member only. Then for loop is used to store all the strings entered by user. Sorting is done in Ascending Order. To sort strings in alphabetical order in Java programming, you have to ask to the user to enter the two string, now start comparing the two strings, if found then make a variable say temp of the same type, now place the first string to the temp, then place the second string to the first, and place temp to the second string and continue. Here is a quote from The Java Programming Language by Arnold, Gosling, ... not by their localized notion of order." The order is based on return value (an integer number, say x) of the compareTo() method: obj1 > obj2 if x > 0. obj1 < obj2 if x < 0. obj1 equals obj2 if x = 0. Here’s how to sort names alphabetically in java or java program to sort names in an alphabetical order. If you are truly comparing Strings alphabetically to arrange them in order, use compareTo() method from Comparable interface in Java. Everything I've been able to find online (including the forums here) has suggested to use the Comparator class, or to put the strings into an array, and sort list- I really would like to stick with just the String class, and its methods please. ). I didn't want to paste the entire program. Java Comparable interface is used to order the objects of the user-defined class. It also compare String based upon there value, and can be used to sort String alphabetically, if they are stored in List using Collections. If you are truly comparing Strings alphabetically to arrange them in order, use compareTo() method from Comparable interface in Java. This interface is found in java.lang package and contains only one method named compareTo(Object). Sort List of Names or Strings in Alphabetical Order Java. Sort Strings. Sorting string array alphabetically – String.compareTo We are going to write a program which will work ask for 2. Using Built-in Functions: compareTo() of String Class and sort() of Arrays Class. String.compareTo(String) can be dangerous to use, depending on the context. compareTo() method can be accessed by the instance of String class. CompareTo() is used to compare two strings lexicographically. The following section will show you how to make a custom class comparable (and thus sortable). 2. sort() method. The natural ordering is defined by implementation of the compareTo() method which determines how the current object (obj1) is compared to another (obj2) of the same type. For that, we will use the String class compareTo() method.. compareTo() in Java. It also compare String based upon there value, and can be used to sort String alphabetically, if they are stored in List using Collections.sort() method. So we need to compare two strings alphabetically i.e character by character. Method syntax is: public int compareTo(T o); Java sort arraylist of objects – Comparable Example. The order resulting from the compareTo() method is called “natural order”: Strings are sorted alphabetically; dates and times are sorted in chronological order. Each character of both strings is converted into its unicode value.Lexicographical order is nothing but alphabetical order. compareTo() method is used to compare first letter of each string to store in alphabetical order . java sort string array alphabetically, Java program to sort strings array in alphabetical order 1. compareTo() is a String class method which returns the lexicographical difference between two Strings(i.e compares two strings lexicographically). Java Comparable Example This method returns an int data-type which is based on the comparison between the two string. Comparable interface provides one method compareTo(T o) to implement in any class so that two instances of that class can be compared.