When we throw an IllegalArgumentException object within a method, that method must advertise it in the method signature.这句话是对的还是错的
时间: 2023-10-03 07:04:31 浏览: 56
这句话是错的。在 Java 中,方法可以抛出非受检异常(unchecked exceptions)例如 IllegalArgumentException,而无需在方法签名中声明它们。只有受检异常(checked exceptions)需要在方法签名中声明。受检异常是指必须捕获或声明的异常,否则编译器会产生错误。而非受检异常是指不需要捕获或声明的异常,例如 RuntimeException。
相关问题
5. Please Define your own exception class MyException(Show message: HAVE ERRORs) and throw this exception object in your method(6 points)
Sure! Here's an example implementation of the MyException class and how to throw it within a method:
```python
class MyException(Exception):
def __init__(self, message):
self.message = message
super().__init__(self.message)
def my_method(param):
if param < 0:
raise MyException("Input parameter must be non-negative")
# rest of method code here
# example usage
try:
my_method(-1)
except MyException as e:
print("Caught exception:", e.message)
```
In this example, the `MyException` class extends the built-in `Exception` class and defines a custom error message. The `my_method` function checks if the input parameter is non-negative, and if it's not, it raises a `MyException` object with the custom error message. The `try`/`except` block then catches the exception and prints the error message.
In preparation for a class Fraction, create a class NullDenominatorException that must be a checked exception whose instances are thrown if the denominator of an object of class Fraction is 0.
Sure, here's an example implementation of the NullDenominatorException class in Java:
```
public class NullDenominatorException extends Exception {
public NullDenominatorException() {
super("Denominator cannot be null or zero.");
}
}
```
In this implementation, we extend the built-in Exception class to create our custom exception. We also provide a constructor that sets the exception message to a default value of "Denominator cannot be null or zero.". This message will be displayed when the exception is thrown.
To use this exception in our Fraction class, we can add a check for a null or zero denominator in the constructor and throw the exception if necessary. Here's an example implementation of the Fraction class:
```
public class Fraction {
private int numerator;
private int denominator;
public Fraction(int numerator, int denominator) throws NullDenominatorException {
if (denominator == 0) {
throw new NullDenominatorException();
}
this.numerator = numerator;
this.denominator = denominator;
}
// other methods for adding, subtracting, multiplying, and dividing Fractions
}
```
In this implementation, we check if the denominator is 0 and throw a NullDenominatorException if it is. Otherwise, we set the numerator and denominator instance variables and continue with the construction of the Fraction object.