13ajdf39.blog this is what it is. the data nefariously for the climate alarmist agenda. not because the science is better, but because they want people scared. can't argue with that. it's straight pants-on-head level stupid. you'll never see goalposts move as often as arguing with someone living in denial. if not that it'll be any of dozens of popular bs\ excuses [skepticalscience.com/argument ​ \blog science - all the convenience of looking like science without that inconvenient peer review tony abbott is a but he's a pretty smart guy. he refuses to believe.
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The first line declares a variable named num, but it does not actually contain a primitive value yet. Instead, it contains a pointer (because the type is Integer which is a reference type). Since you have not yet said what to point to, Java sets it to null, which means "I am pointing to nothing". In the second line, the new keyword is used to instantiate (or create) an object of type Integer and the pointer variable num is assigned to that Integer object. The NullPointerException occurs when you declare a variable but did not create an object. So you are pointing to something that does not actually exist. If you attempt to dereference num BEFORE creating the object you get a NullPointerException. In the most trivial cases, the compiler will catch the problem and let you know that "num may not have been initialized," but sometimes you may write code that does not directly create the object. For instance, you may have a method as follows: |
NullPointerExceptions are exceptions that occur when you try to use a reference that points to no location in memory (null) as though it were referencing an object. Calling a method on a null reference or trying to access a field of a null reference will trigger a NullPointerException. These are the most common, but other ways are listed on the NullPointerException javadoc page.
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