attempt to invoke virtual method on a null Object (NullPointerException)
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What is a NullPointerException, and how do I fix it?
94683
Implement a pure virtual method in Objective-C
98080
Android: Cannot invoke toString() on the primitive type int
12296
How can I return NULL from a generic method in C#?
8738
Should a retrieval method return 'null' or throw an exception when it can't produce the return value?
79246
virtual methods
18250
What could cause java.lang.reflect.InvocationTargetException?
79586
System.NullPointerException: Attempt to de-reference a null object
89755
Why is "throw null" not creating a compilation error in Java?
8808
Strange Java null behavior in Method Overloading
23964
Why does Java have a "NullPointerException" when there are no pointers in Java?
111314
What is the difference between an abstract method and a virtual method?
146476
Java: Why aren't NullPointerExceptions called NullReferenceExceptions?
128142
java.lang.NullPointerException at org.apache.jsp.foo_jsp._jspInit(foo_jsp.java:22)
85964
Android: ClassNotFoundException when passing serializable object to Activity
81518
Find out what variable is throwing a NullPointerException programmatically
98908
Is it good practice to set variables to null when they are no longer needed?