59 lines
1.1 KiB
C++
59 lines
1.1 KiB
C++
#include <iostream>
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using namespace std;
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void changeInteger(int n);
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void changeIntegerPerPointer(int* pN);
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int changeIntegerPerReturn(int n);
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void changeIntegerPerReference(int& n);
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int main()
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{
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// general
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int* pNumber = nullptr;
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pNumber = new int(0);
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cout << "size of pNumber: " << sizeof(pNumber) << endl;
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cout << "size of pNumber data: " << sizeof(*pNumber) << endl;
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*pNumber = 567;
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//pNumber = new int(0); // BAD BAD - Memory Leak, because we override an existing pointer address with a new one without saving the old one
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// here are 100s of lines of code
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if (pNumber != nullptr)
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{
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delete pNumber;
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pNumber = nullptr;
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}
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// pointer as references
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int number = 0;
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changeInteger(number);
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changeIntegerPerPointer(&number);
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changeIntegerPerPointer(pNumber);
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changeIntegerPerReference(number);
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return 0;
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}
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void changeInteger(int n)
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{
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n = 100;
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}
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void changeIntegerPerPointer(int* pN)
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{
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cout << "address of pN: " << &pN << endl;
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if (pN == nullptr) return; // BE CAREFUL - if you don't what you get, do a test before
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*pN = 200;
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}
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void changeIntegerPerReference(int& n)
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{
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n = 300;
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}
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