How does a Java method throw an exception before it's called?

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Aryan Kumar · Answer

A Java method cannot throw an exception before it's called. The throw keyword is used to throw an exception, and it is only valid within the body of a method. Therefore, a method cannot throw an exception before it's even called.

However, a method can declare that it can throw an exception. This is done using the throws keyword in the method declaration. For example, the following method declaration declares that the readFile() method can throw an IOException exception:

public void readFile(String fileName) throws IOException {
  // ...
}

This declaration does not actually throw an exception. It simply tells the compiler that the readFile() method might throw an exception. If the readFile() method does throw an exception, the exception will be thrown when the readFile() method is called.

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How does a Java method throw an exception before it's called?

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