In this tutorial, we will see examples of few frequently used exceptions. If you looking for exception handling tutorial refer this complete guide: Exception handling in Java.
Example 1: Arithmetic exception
Class: Java.lang.ArithmeticException
This is a built-in-class present in java.lang package. This exception occurs when an integer is divided by zero.
class Example1 { public static void main(String args[]) { try{ int num1=30, num2=0; int output=num1/num2; System.out.println ("Result: "+output); } catch(ArithmeticException e){ System.out.println ("You Shouldn't divide a number by zero"); } } }
Output of above program:
You Shouldn't divide a number by zero
Explanation: In the above example I’ve divided an integer by a zero and because of this ArithmeticException
is thrown.
Example 2: ArrayIndexOutOfBounds Exception
Class: Java.lang.ArrayIndexOutOfBoundsException
This exception occurs when you try to access the array index which does not exist. For example, If array is having only 5 elements and we are trying to display 7th element then it would throw this exception.
class ExceptionDemo2 { public static void main(String args[]) { try{ int a[]=new int[10]; //Array has only 10 elements a[11] = 9; } catch(ArrayIndexOutOfBoundsException e){ System.out.println ("ArrayIndexOutOfBounds"); } } }
Output:
ArrayIndexOutOfBounds
In the above example the array is initialized to store only 10 elements indexes 0 to 9. Since we are try to access element of index 11, the program is throwing this exception.
Example 3: NumberFormat Exception
Class: Java.lang.NumberFormatException
This exception occurs when a string is parsed to any numeric variable.
For example, the statement int num=Integer.parseInt ("XYZ");
would throw NumberFormatException
because String
“XYZ” cannot be parsed to int.
class ExceptionDemo3 { public static void main(String args[]) { try{ int num=Integer.parseInt ("XYZ") ; System.out.println(num); }catch(NumberFormatException e){ System.out.println("Number format exception occurred"); } } }
Output:
Number format exception occurred
Example 4: StringIndexOutOfBound Exception
Class: Java.lang.StringIndexOutOfBoundsException
- An object of this class gets created whenever an index is invoked of a string, which is not in the range.
- Each character of a string object is stored in a particular index starting from 0.
- To get a character present in a particular index of a string we can use a method charAt(int) of java.lang.String where int argument is the index.
E.g.
class ExceptionDemo4 { public static void main(String args[]) { try{ String str="beginnersbook"; System.out.println(str.length());; char c = str.charAt(0); c = str.charAt(40); System.out.println(c); }catch(StringIndexOutOfBoundsException e){ System.out.println("StringIndexOutOfBoundsException!!"); } } }
Output:
13 StringIndexOutOfBoundsException!!
Exception occurred because the referenced index was not present in the String.
Example 5: NullPointer Exception
Class: Java.lang.NullPointer Exception
An object of this class gets created whenever a member is invoked with a “null” object.
class Exception2 { public static void main(String args[]) { try{ String str=null; System.out.println (str.length()); } catch(NullPointerException e){ System.out.println("NullPointerException.."); } } }
Output:
NullPointerException..
Here, length() is the function, which should be used on an object. However in the above example String
object str is null so it is not an object due to which NullPointerException
occurred.
Shraban says
It would be better if you describe “Exception Handling with Method Overriding.”
N3al says
good examples really enjoyed they are straight forward
muthukumar says
very useful!!!