C++快速入门第四篇(动态内存申请与内存池)

每一篇博客我都会修改很多次,同学们可以放心浏览.

现在是2022 /5/4 长春市大学生因疫情返乡,我也不例外,所以时间比较少.很难抽出时间整理博客,疫情何时能结束呢?

#include 
#include 
using namespace std;

int main() {

	
	int* pC_Num = (int*)malloc(sizeof(int));
	free(pC_Num);
	pC_Num = nullptr;						

	
	int* pCpp_Num = new int;
	delete pCpp_Num;						
	pCpp_Num = nullptr;

	
	int* pC_Array = (int*)malloc(sizeof(int) * 4);
	free(pC_Array);
	pC_Array = nullptr;

	
	int* pCpp_Array = new int[4];
	delete[] pCpp_Array;					
	pCpp_Array = nullptr;

	
	

	return 0;

}

#include 
#include 
using namespace std;

int main() {
	
	
	int* pAlloc = (int*)calloc(sizeof(int), 3);	
	
	if (pAlloc == nullptr) {
		return 0;
	}
	//assert(pAlloc);	                        
	
	cout << pAlloc[0] << pAlloc[1] << pAlloc[2] << endl;
	free(pAlloc);

	
	int* pArray = new int[3]{ 1,2,3 };	        
	cout << pArray[0] << pArray[1] << pArray[2] << endl;
	delete[] pArray;
	pArray = nullptr;		                    

	return 0;

}

#include 
#include 
#include 
#include 
using namespace std;

int main() {
	
	

	
	
	char* Memory = new char[1024];
	assert(Memory);										
	
	int* pInt = new(Memory + 0) int[3]{1,2,3};			
	assert(Memory);								
	
	char* pChar = new(Memory + 12) char[20];			
	assert(pChar);
	strcpy(pChar, "我很帅,你也不错");					

	
	cout << pInt[0] << pInt[1] << pInt[2] << endl;
	cout << ((int*)Memory)[0] << ((int*)Memory)[1] << ((int*)Memory)[2] << endl;
	
	
	cout << pChar << endl;
	cout << Memory + 12 << endl;		
	
	delete[] Memory;
	Memory = nullptr;

	return 0;

}