How to Create Object in Java: Syntax and Examples

In Java, you create an object by using the new keyword followed by a class constructor, like ClassName obj = new ClassName();. This allocates memory and initializes the object so you can use it in your program.

Syntax

To create an object in Java, you use the new keyword followed by the class name and parentheses. This calls the class constructor to make a new instance.

• ClassName: The name of the class you want to create an object from.
• obj: The variable that will hold the reference to the new object.
• new: Keyword that creates the object in memory.
• (): Parentheses call the constructor method.

java

ClassName obj = new ClassName();

Example

This example shows how to create an object of a simple Car class and use it to call a method.

java

public class Car {
    String color;

    // Constructor
    public Car(String color) {
        this.color = color;
    }

    // Method to display car color
    public void displayColor() {
        System.out.println("Car color is: " + color);
    }

    public static void main(String[] args) {
        // Create a Car object
        Car myCar = new Car("red");

        // Use the object
        myCar.displayColor();
    }
}

Output

Car color is: red

Common Pitfalls

Beginners often forget to use the new keyword or confuse the class name with the object name. Another mistake is not calling a constructor properly or missing parentheses.

Wrong: Car myCar = Car(); (missing new)
Right: Car myCar = new Car();

Also, trying to use an object before creating it causes errors.

java

/* Wrong way - missing 'new' keyword */
// Car myCar = Car(); // This will cause a compile error

/* Right way */
Car myCar = new Car();

Quick Reference

Step	Description	Example
1	Declare a variable of the class type	Car myCar;
2	Use 'new' keyword to create the object	myCar = new Car();
3	Call constructor with parameters if needed	new Car("blue");
4	Use the object to access methods or fields	myCar.displayColor();

Key Takeaways

Use the 'new' keyword with a class constructor to create an object in Java.

The object variable holds a reference to the created object in memory.

Always include parentheses after the class name to call the constructor.

Forgetting 'new' or parentheses causes compile-time errors.

Create the object before using its methods or fields.