类模板（3种）

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很多初学Cpp的人不懂类模板，在此，我举了3个简单的例子，帮助大家了解语法和基本流程

类模板1：

#include<iostream>using namespace std;template<class T>//相当于template<typename/class numtype(类型)>class Compare{   public:      Compare(T a, T b);      T max();      T min();   private:      T x, y;};template<class T>Compare<T> :: Compare(T a,T b) {      x = a;      y = b; } template<class T> T Compare<T> :: max() {     return (x > y) ? x : y; } template<class T> T Compare<T> :: min() {     return (x < y) ? x : y; }int main(){   Compare<int>cmp1(3, 7);//这里的Compare不是类名了，而是类的模板名，注意调用的形式，中间加上虚拟类型,跟以往的不一样   cout<<cmp1.max()<<" is the maxnum between a and b"<<endl;   cout<<cmp1.min()<<" is the minnum between a and b"<<endl;   Compare<float>cmp2(6.4, 8.5);   cout<<cmp2.max()<<" is the maxnum between a and b"<<endl;   cout<<cmp2.min()<<" is the minnum between a and b"<<endl;   system("pause");   return 0;}

类模板2：

#include<iostream>#include<cstdlib>using namespace std;template<class T>class Array{   private:      T*set;      int n;   public:      Array(T *data, int i){set = data; n = i;}      void sort();       T sum();      void display();};template<class T>void Array<T> :: sort(){   int i,j;   T temp;   for(i = 0;i < n - 1; i++)     for(j = 0;j < n - 1 - i; j++)       if(set[j] > set[j+1])//指针名[i]即元素，如p[i]等同于*(p+i)以及*(a+i),不需加星号了       {         temp = set[j];         set[j] = set[j+1];         set[j+1] = temp;       }}template<class T>T Array<T> :: sum(){ int i;T s = 0;for(i = 0;i < n;i++)  s + =set[i];return s;}template<class T>void Array<T> :: display(){ int i; for(i = 0;i < n;i++)  cout<<"数组的第"<<i+1<<"个元素为:"<<set[i]<<endl;}int main(){   int a[10] = {9,8,7,1,2,3,4,6,5,10};   float b[9] = {1.2,2.3,4.6,3.2,2.1,9.8,2.4,9.1,10.1};   Array<int>a1(a,10);   Array<float>b1(b,9);   cout<<"a数组的原始序列为:"<<endl;   a1.display();   a1.sort();   cout<<"a数组的排序后序列为:"<<endl;   a1.display();   cout<<"a数组元素之和为:"<<a1.sum()<<endl;   cout<<"---------------------------"<<endl;   cout<<"b数组的原始序列为:"<<endl;   b1.display();   b1.sort();   cout<<"b数组的排序后序列为:"<<endl;   b1.display();   cout<<"b数组元素之和为:"<<b1.sum()<<endl;   system("pause");   return 0;}

类模板3：

#include<iostream>#include<cstdlib>using namespace std;template<class T,int N>//T为类型,N为数值,类模板里面包含多个参数 class A{   private:      T a[N];   public:      A();//无参构造函数对应无参对象       void show();      void sh();};template<class T,int N>A<T,N> :: A(){   for(int i = 0;i < N; i++)  {     cout<<"input a["<<i<<"]:";     cin>>a[i];  }}template<class T, int N>void A<T, N> :: show(){   cout<<"N = "<<N<<endl;}template<class T, int N>void A<T, N> :: sh(){for(int i = 0;i < N;i++) cout<<"a["<<i<<"] = "<<a[i]<<endl;}int main(){   A<float, 5>a;//直接定义对象，对应构造函数，不需要再为蛇添足，使用对象调用构造函数    a.show();   a.sh();   system("pause");   return 0;}