Here, we will follow the below-mentioned points to understand and eradicate the error alongside checking the outputs with minor tweaks in our sample code
- Introduction about the error with example
- Explanation of dereferencing in detail
- Finally, how to fix the issue with Example code and output.
If You Got this error while you’re compiling your code? Then by the end of this article, you will get complete knowledge about the error and able to solve your issue, lets start with an example.
Example 1:
Java
// Java Program to Illustrate Dereference// Importing required classesimport java.io.*;import java.util.*;// Main classclass GFG { // Main driver method public static void main(String[] args) { // Reading input from keyboard by // creating object of Scanner class Scanner sc = new Scanner(System.in); // Taking input for two integer variables int a = sc.nextInt(); int b = sc.nextInt(); // Calculating sum of two variables and storing the // value in sum variable int sum = a + b; // Print and display resultant length System.out.println(sum.length); }} |
Output:
So this is the error that occurs when we try to dereference a primitive. Wait hold on what is dereference now?. Let us do talk about that in detail. In Java there are two different variables are there:
- Primitive [byte, char, short, int, long, float, double, boolean]
- Objects
Since primitives are not objects so they actually do not have any member variables/ methods. So one cannot do Primitive.something(). As we can see in the example mentioned above is an integer(int), which is a primitive type, and hence it cannot be dereferenced. This means sum.something() is an INVALID Syntax in Java.
Explanation of Java Dereference and Reference:
- Reference: A reference is an address of a variable and which doesn’t hold the direct value hence it is compact. It is used to improve the performance whenever we use large types of data structures to save memory because what happens is we do not give a value directly instead we pass to a reference to the method.
- Dereference: So Dereference actually returns an original value when a reference is Dereferenced.
What dereference Actually is?
Dereference actually means we access an object from heap memory using a suitable variable. The main theme of Dereferencing is placing the memory address into the reference. Now, let us move to the solution for this error,
How to Fix “int cannot be dereferenced” error?
Note: Before moving to this, to fix the issue in Example 1 we can print,
System.out.println(sum); // instead of sum.length
Calling equals() method on the int primitive, we encounter this error usually when we try to use the .equals() method instead of “==” to check the equality.
Example 2:
Java
// Main classpublic class GFG { // Main driver method public static void main(String[] args) { // Declaring and initialising the variable // with integer value int gfg = 5; // Checking the equality using .equals() method if (gfg.equals(5)) { // Print statement System.out.println("The value of gfg is 5"); } else { // Print statement System.out.println("The value of gfg is not 5"); } }} |
Output:
Still, the problem is not fixed. We can fix this issue just by replacing the .equals() method with”==” so let’s implement “==” symbol and try to compile our code.
Example 3:
Java
public class EqualityCheck { public static void main(String[] args) { int gfg = 5; // Instead of .equals method here we have used "==" // symbol to check the equality if (gfg == 5) { System.out.println("The value of gfg is 5"); } else { System.out.println("The value of gfg is not 5"); } }} |
The value of gfg is 5
This is it, how to fix the “int cannot be dereferenced error in Java.
