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What is the difference between checked and unchecked exceptions in java? Why do we throw using 'throws' exception instead of catching them?

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already asked on so: stackoverflow.com/questions/6115896/… –  Zavior Oct 28 at 10:50
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The answer to this question can be found on Stack Overflow - stackoverflow.com/questions/6115896/… –  ChrisF♦ Oct 28 at 11:37

put on hold as off-topic by Kilian Foth, Philipp, ChrisF♦ Oct 28 at 11:37

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1 Answer

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A checked exception requires that you add a throws declaration to the method signature, or you add a try catch block around it.

public void checked() throws IOException {
  throw new IOException(); // compiles just fine
}

public void checked() {
  try {
    throw new IOException();
  } catch (IOException e) {
    // ...
  }
}

This will not work:

public void checkedWithoutThrows() {
  throw new IOException(); // will not compile
}

An unchecked exception does not need this.

public void unchecked() {
  throw new RuntimeException();
}

And, just for completeness, the way to determine unchecked from checked exceptions is that unchecked exceptions all descend from RuntimeException at some point or another.

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Thanks KepaniHaole, It is very helpful for me. Your examples are very easy to understand. Can you please tell me about the difference between 'throw' and 'throws'?? –  Arnav Kumar Oct 28 at 11:42

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