All Flashcards
What is a method?
A block of code that performs a specific task.
What is a void method?
A method that performs an action but does not return a value.
What is a non-void method?
A method that performs an action and returns a value.
What is a static method?
A method that belongs to the class itself, not to any specific object.
What is a non-static method?
A method that operates on a specific object.
What is a method signature?
The method name and the parameter list (types and names of inputs).
Define 'parameter'.
Input values that a method can accept to modify its behavior.
What does 'dot notation' refer to?
The way to call methods using the class/object name, a dot, and the method name.
What is the purpose of methods?
To organize code into reusable blocks, making programs more modular and easier to manage.
What is the behavior of a method?
The actions an object can perform.
What is the significance of the void keyword in a method header?
It indicates that the method does not return a value.
How do you call a static method?
Use the class name and dot notation: ClassName.methodName();
How do you call a non-static method?
Use the object name and dot notation: objectName.methodName();
Why is the method signature important?
It's crucial for the compiler to identify and call the correct method.
What happens when a method is called?
The program jumps to the method's code, executes it, and returns to the point where it was called.
What are methods essential for?
Organizing code into reusable blocks and making programs more modular.
What is the role of parameters in methods?
They allow methods to accept input values, modifying their behavior.
What does a method signature consist of?
The method name and the parameter list.
What is the purpose of static methods?
They belong to the class and act as general tools for any object of the class.
What is the purpose of non-static methods?
They operate on a specific object, with each object having its own version.
Identify the error:
java
public class Example {
public void myMethod(int a) {
System.out.println(a);
}
public static void main(String[] args) {
myMethod(5);
}
}
myMethod is not static and cannot be called directly from the static main method. An object of the Example class must be created first.
What is the output?
java
public class Test {
public static void printMessage() {
System.out.println("Hello");
}
public static void main(String[] args) {
Test.printMessage();
}
}
Hello
Complete the code to call the setName method on myDog:
java
Dog myDog = new Dog();
// Complete the line below
__________;
myDog.setName("Buddy");
Identify the error:
java
public class MathUtils {
public int add(int a, int b) {
return a + b;
}
public static void main(String[] args) {
System.out.println(add(5, 3));
}
}
The add method is not static and cannot be called directly from the static main method without creating an object of the MathUtils class.
What is the output?
java
public class Counter {
public int count = 0;
public void increment() {
count++;
}
public static void main(String[] args) {
Counter c = new Counter();
c.increment();
System.out.println(c.count);
}
}
1
Complete the code to call the static method incrementMinimumWage from the class Salary:
java
// Complete the line below
__________;
Salary.incrementMinimumWage();
Identify the error:
java
public class Printer {
public void print(String message) {
System.out.println(message);
}
public static void main(String[] args) {
String msg = "Hello, world!";
Printer.print(msg);
}
}
The print method is not static and cannot be called directly using the class name. An object of the Printer class must be created first.
What is the output?
java
public class Greeter {
public void greet(String name) {
System.out.println("Hello, " + name + "!");
}
public static void main(String[] args) {
Greeter g = new Greeter();
g.greet("Alice");
}
}
Hello, Alice!
Complete the following code to create an object of type Car called myCar and then call the method setMake with the argument "Toyota".
java
public class Car {
String make;
public void setMake(String newMake) {
make = newMake;
}
public static void main(String[] args) {
// Complete the code below
}
}
java
Car myCar = new Car();
myCar.setMake("Toyota");
What is the output?
java
public class Calculator {
public int square(int num) {
return num * num;
}
public static void main(String[] args) {
Calculator calc = new Calculator();
System.out.println(calc.square(5));
}
}
25