Multiple Choice Questions: Pass by Value with Primitive Types in Java

📚 Quick Study Guide

• 🧠 Pass by Value: In Java, when you pass a primitive type (like `int`, `float`, `boolean`) to a method, you are passing a copy of the value.
• 📝 Original Unaffected: Any changes made to the parameter inside the method do not affect the original variable outside the method.
• 🔢 Primitive Types: Common primitive types include `int`, `double`, `float`, `boolean`, `char`, `byte`, `short`, and `long`.
• 💡 Example: If you pass an `int x = 5` to a method, the method receives a copy of `5`. Changing this copy won't change the original `x`.

Practice Quiz

1. Which of the following statements best describes 'pass by value' for primitive types in Java?
   1. The method receives a reference to the original variable.
   2. The method receives a copy of the variable's value.
   3. The method can directly modify the original variable.
   4. The method cannot access the variable at all.
2. What happens to the original variable when its value is changed inside a method using 'pass by value'?
   1. The original variable is also changed.
   2. The original variable remains unchanged.
   3. A new variable with the same name is created.
   4. An error occurs.
3. Which of the following is NOT a primitive data type in Java?
   1. `int`
   2. `String`
   3. `boolean`
   4. `double`
4. Consider the following code:

   void changeValue(int x) {
    x = 10;
   }
   
   int main() {
    int y = 5;
    changeValue(y);
    System.out.println(y);
   }
     

   What will be the output?
   1. `5`
   2. `10`
   3. `15`
   4. An error.
5. Which of the following primitive types are passed by value in Java?
   1. Only `int` and `boolean`.
   2. All primitive types.
   3. Only `float` and `double`.
   4. Only `char` and `byte`.
6. What is the purpose of 'pass by value' in Java?
   1. To allow methods to directly modify the original variables.
   2. To create a copy of the data, ensuring the original data remains unchanged.
   3. To improve performance by avoiding copying data.
   4. To simplify memory management.
7. If you want a method to change the value of an `int` passed to it, what should you do?
   1. Use 'pass by reference'.
   2. Wrap the `int` in an object (like `Integer`) and pass the object.
   3. Declare the `int` as `final`.
   4. It's impossible to change the value of an `int` passed to a method.