21. Similarly, the successor can be found by going right once and left until a null pointer is found. 22. Dereferencing a null pointer is illegal. 23. A null pointer is a pointer in a computer program that does not point to any object or function. 24. C doesn't have strings at all, but does have " null pointers ", which are also a weird concept. 25. If either of those assumptions is wrong, one of the methods will be invoked on null, producing a null pointer error. 26. During compilation time these are initialized by language specific rules ( to undefined values, 0, NULL pointers , . . . ). 27. C + + 11 corrects this by introducing a new keyword to serve as a distinguished null pointer constant : nullptr. 28. However, the internal representation of the null pointer may be any bit pattern ( possibly different values for different data types ). 29. For example, if the expected type is int *, then a null pointer should be passed as ( int * ) NULL. 30. Since the dawn of C in 1972, the constant 0 has had the double role of constant integer and null pointer constant.
