Pointer question.

The first assignment will allocate 100 characters and store the pointer in string. The second assignment will allocate 300 characters and store that pointer in string. It will not contain the same data; new is like a malloc call. You'd also want to free that memory before you call new again, because it won't be deallocated (creating a memory leak).

This will compile, but it doesn't work, your old values will be lost and the program will leak memory. There are two possible solutions.
Use realloc, you should only do this in C style code

char* string = (char*)malloc(100);strcpy(string, otherthing);string = (char*)realloc(string,300);

Use a std::string (for strings) or a std::vector (for lists of other objects):

std::string string = otherthing;string += "make it longer"; // string will grow automaticly

you will produce a memory leak with this. if you call new you create a memory chunk. you then just store a pointer to it in your variable. you need to delete that pointer first before you can assign a newly create memory chunk to this variable or your memory chunk starts floating around cluttering memory.

with new/delete you can not relallocate memory. so you need to:
- create a new memory
- story it temporary (in another variable)
- copy things over
- free old memory pointer
- move pointer from temporary variable into old variable

string is now longer and contains the original data, and there are no memory leaks (assuming you delete [] string at the end of your program and you're done).