1. Introduction

In Java, comparing two strings is a common operation. We often need to check whether two strings are the same or which one comes first lexicographically. The equals() and compareTo() methods are typically used for this purpose in Java.

2. Program Steps

1. Define the main method as the entry point of the program.

2. Declare and initialize two strings to be compared.

3. Use the equals() method to check if the two strings are equal.

4. Use the compareTo() method to compare the two strings lexicographically.

5. Print the result of the comparisons.

3. Code Program

public class CompareStrings {
    public static void main(String[] args) {
        // Step 2: Declare and initialize two strings to be compared
        String string1 = "Java";
        String string2 = "Java";
        String string3 = "java";

        // Step 3: Use the equals() method to check if the two strings are equal
        boolean isEqual1 = string1.equals(string2);
        boolean isEqual2 = string1.equalsIgnoreCase(string3);

        // Step 4: Use the compareTo() method to compare the two strings lexicographically
        int comparison1 = string1.compareTo(string2);
        int comparison2 = string1.compareToIgnoreCase(string3);

        // Step 5: Print the result of the comparisons
        System.out.println(string1 + " equals " + string2 + ": " + isEqual1);
        System.out.println(string1 + " equalsIgnoreCase " + string3 + ": " + isEqual2);
        System.out.println(string1 + " compareTo " + string2 + ": " + comparison1);
        System.out.println(string1 + " compareToIgnoreCase " + string3 + ": " + comparison2);
    }
}

Output:

Java equals Java: true
Java equalsIgnoreCase java: true
Java compareTo Java: 0
Java compareToIgnoreCase java: 0

4. Step By Step Explanation

– Step 1: The main method is defined as the entry point of the program.

– Step 2: Two strings, string1 and string2, are declared and initialized. Another string string3 is also declared and initialized with a different case.

– Step 3: The equals() method is used to check if string1 and string2 are equal. The equalsIgnoreCase() method is used to check if string1 and string3 are equal regardless of their case.

– Step 4: The compareTo() method is used to compare string1 and string2 lexicographically. The compareToIgnoreCase() method is used to compare string1 and string3 lexicographically, ignoring case differences.

– Step 5: The results of the comparisons are printed. When the strings are equal, equals() returns true and compareTo() returns 0.