Null vs. Empty Strings in Java: What\'s the Difference?

Understanding the Distinction between Null and Empty Strings

In Java programming, strings play a crucial role. However, the difference between a null string and an empty string ("") can often pose a challenge. Despite seemingly similar, they hold significant distinctions.

What's the Difference?

Null String:

• Represents the absence of a value.
• Assigned as null.
• Cannot be used directly in string operations as it would throw a NullPointerException.

Empty String:

• Represents an empty string with no characters.
• Assigned as "".
• Can be used in string operations without causing errors.

In the provided code snippet:

String a = "";
String b = null;

a is assigned an empty string, while b is assigned null.

System.out.println(a == b); // false

The == operator compares the references of the strings, which are different in this case.

System.out.println(a.equals(b)); // false

The equals method compares the content of the strings. Since b is null and you cannot call methods on null references, it returns false.

To visualize the difference, consider the following analogy:

Null String: A bookshelf with no books. It's empty, but it exists as a physical entity.

Empty String: An empty bookshelf. It has no books, but it's still a bookshelf.

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