Question

I was checking the string comparison methods used for string compsrsion and explore the string class in the decomplier and come to know that there are basically four methods

equals()
equalsIgnoreCase()
compareTo()
compareToIgnore()

Now I want to know the difference between two methods that we use they are equals() and compareTo() , basically please advise why string class had kept both these methods ..

String tv = "Bravia";
        String television = "Bravia";

        // String compare example using equals
        if (tv.equals(television)) {
            System.out.println("Both tv and television contains same letters and equal by equals method of String");
        }

        // String compare example in java using compareTo
        if (tv.compareTo(television) == 0) {
            System.out.println("Both tv and television are equal using compareTo method of String");
        }

output :-

Both tv and television contains same letters and equal by equals method of String
Both tv and television are equal using compareTo method of String

Answer 1

Strings implement Comparable interface and then its bound to implement compareTo method.

Camparable interface

it facilitates ordering of the object when they are contained in any sorted collection. So when you will put your string in any sorted collection(like TreeSet), how will you tell java how to sort your objects. that’s where coompareTo() method comes in seen. it is used by collection to sort your object.

String tv = "Bravia";
    String television = "Bravia";

    // String compare example using equals
    if (tv.equals(television)) {
        System.out.println("Both tv and television contains same letters and equal by equals method of String");
    }

    // String compare example in java using compareTo
    if (tv.compareTo(television) == 0) {
        System.out.println("Both tv and television are equal using compareTo method of String");
    }

    if (tv.compareTo(television) < 0){

    System.out.println("tv comes before  using compareTo method of String");
    }

if (tv.compareTo(television) > 0){

    System.out.println("tv comes after using compareTo method of String");
    }