#Greenfoot null pointer exception code#

If (i >= IntegerCache.low & i <= IntegerCache.high) According to the documentation: getMouseInfo public static MouseInfo getMouseInfo () Return a mouse info object with information about the state of the mouse.

#Greenfoot null pointer exception code#

* inclusive, and may cache other values outside of this range. If you're having a null pointer exception in the code you wrote then that means that your mouseinfo object is null. * This method will always cache values in the range -128 to 127, * to yield significantly better space and time performance by * the constructor #Integer(int)}, as this method is likely * required, this method should generally be used in preference to Try changing the order in remove () to add the score before you remove yourself from the world. In this case, getWorld () will return null, so you will get a null pointer exception. Wenn seit dem letzten Aufruf der Methode keine Taste gedrckt wurde, wird null zurckgegeben. delete() has to be careful about null pointers. You are calling getWorld () in addScore () after you removed yourself from the world. Greenfoot (GreenfootDE20)-> 'Liefert die zuletzt gedrckte Taste zurck (seit dem letzten Aufruf). This implies that an array is never copied as a whole when named as an argument to a function, but rather only the address of its first element is passed. Removing an element not in a set will result in a null pointer being passed to. * Returns an Integer} instance representing the specified Furthermore, in most expression contexts (a notable exception is as operand of sizeof), an expression of array type is automatically converted to a pointer to the array's first element. īecause ：a1 b1 All of them get data from the constant light pool Its name is confusing because it is not possible to create pointers explicitly in Java But it has been around since the very start of the Java language, and wisely, the Java designers never change anything that would break existing code, so the confusing name remains. stay Java in 1 Within byte size Integer（-128 To 127） All exist in a constant pool ,（ It doesn't contain new Integer(xx) initialization ）, So their quotation is the same. NullPointerException is an Exception which Java can throw at runtime. Same as String pool Allied ,Java Integer in （Integer object, Not the basic type ）pool.