Array类模板实现

小咪咪 2022-05-15 13:24 455阅读 0赞

**Array类模板实现**

**---------------------------------------------Array.h------------------------------------------------------**

**\#include<string>  
using namespace std;**

**template<class DataType>  
class Array  
\{  
public:  
/\*  
Array(int szie);  
inline DataType &operator\[\](int index);  
void changeSize(int newSize);  
inline int length() const;  
string err() const;  
\*/  
Array(int size)  
\{  
if(size<1)  
\{  
capacity = 1;  
errorCode = 1;  
\}  
else  
\{  
capacity = size;  
errorCode = 0;  
\}  
elements = new DataType\[capacity\];  
\}**

**inline DataType &operator \[\](int index)  
\{  
\#ifdef DEBUG\_ARRAY  
if(index<0||index>=capacity)  
\{  
errorCode |=2;  
return dud;  
\}  
\#endif  
return elements\[index\];  
\}**

**void changeSize(int newSize)  
\{  
if(newSize<1)  
\{  
errorCode |=4;  
return;  
\}  
DataType \*newArray = new DataType\[newSize\];  
int limit = (newSize>capacity)?capacity:newSize;  
for(int i = 0;i < limit;i++)  
newArray\[i\] = elements\[i\];  
delete\[\] elements;  
elements = newArray;  
capacity = newSize;  
\}**

**inline int length() const  
\{  
return capacity;  
\}**

**string err() const  
\{  
if(errorCode==0)  
return "No error.\\n";**

**string errorMessage = "";  
if(errorCode&1)  
\{  
errorMessage +="Nonpositive size passed into constructor,so\\n";  
errorMessage +="the capacity was set to 1 by default.\\n";  
\}  
if(errorCode&2)  
\{  
errorMessage +="Index out of range.\\n";  
\}  
if(errorCode&4)  
\{  
errorMessage += "Nonpositive size passed into changeSize,so\\n";  
errorMessage += "the size of the array was not change.\\n";  
\}  
return errorMessage;  
\}  
private:  
DataType \*elements;  
int capacity;  
DataType dud;  
int errorCode;  
\};**

**---------------------------------- 主函数（使用Array）------------------------------------------**

**// 各种类模板实现.cpp : Defines the entry point for the console application.  
//  
\#include "stdafx.h"  
\#include<iostream>  
\#include "Array.h"  
\#define DEBUG\_ARRAY  
using namespace std;**

**void getElements( Array<int> &numbers);**

**float calcAverage( Array<int> avnums);**

**int \_tmain(int argc, \_TCHAR\* argv\[\])  
\{  
Array<int> nums(2);  
getElements(nums);  
float average = calcAverage(nums);  
cout<<"The average is:"<<average<<endl;  
cout<<endl;  
system("pause");  
return 0;  
\}**

**void getElements(Array<int> &numbers)  
\{  
int i = 0;  
cout<<"Enter a positive integer:";  
cin >> numbers\[i\];  
while(numbers\[i\] !=-1)  
\{  
i++;  
if(i == numbers.length())  
numbers.changeSize(2\*i);  
cout<<"Enter a positive integer(enter -1 to end):";  
cin>>numbers\[i\];  
\}  
numbers.changeSize(i);**

**cout<<"getElemens:"<<numbers.err()<<endl;**

**\}**

**float calcAverage(Array<int> avnums)  
\{  
int sum = 0;  
for(int i=0;i<avnums.length();i++)  
sum += avnums\[i\];  
cout<<"calcAverage:"<<avnums.err()<<endl;  
return sum/(float)(avnums.length());  
\}**