使用带数组法的函数进行第一份拷贝。使用带指针表示法和指针递增的函数进行第二份拷贝。把目标数组名和待拷贝的元素个数作为前两个函数的参数。第3个函数以目标数组名、源数组名和指向源数组最后一个元素后面的元素的指针。也就是说,给定以下声明,则函数调用如下所示:
double source[5]={1.1,2.2,3.3,4.4,5.5}; double target1[5]; double target2[5]; double target3[5]; copy_arr(target1,source,5); copy_ptr(target2,source,5); copy_ptrs(target3,source,source+5);
源程序:
#include <iostream> #include <Windows.h> using namespace std; void copy_arr(double target1[],double source[],int len) { for(int i=0;i<len;i++) { target1[i]=source[i]; } } void copy_ptr(double *target2,double *source,int len) { for(int i=0;i<len;i++) { *target2++=*(source+i); } } void copy_ptrs(double *target3,double *source_start,double *source_end) { for(;source_start<source_end;source_start++) { *target3=*source_start; target3++; } } int main(void) { double source[5]={1.1,2.2,3.3,4.4,5.5}; double target1[5]; double target2[5]; double target3[5]; copy_arr(target1,source,5); cout<<"target1:"; for(int i=0;i<sizeof(source)/sizeof(source[0]);i++) { cout<<target1[i]<<" "; } cout<<endl; copy_ptr(target2,source,5); cout<<"target2:"; for(int i=0;i<sizeof(source)/sizeof(source[0]);i++) { cout<<target2[i]<<" "; } cout<<endl; copy_ptrs(target3,source,source+5); cout<<"target3:"; for(int i=0;i<sizeof(source)/sizeof(source[0]);i++) { cout<<target3[i]<<" "; } cout<<endl; system("pause"); return 0; }
运行结果: