strcpy

//strcpy函数的使用

#include<iOStream>
using namespace std;
int main(){
	char a[7] = "abcdef"; //不能写成char a[6] = "abcdef";如果7改成6，编译时报错：ERROR: initializer-string for char array is too long
	char b[4] = "ABC";    //不能写成char a[3] = "ABC";如果4改成3，编译时报错：error: initializer-string for char array is too long

	cout<<"a[0]:"<<a[0]<<endl;
	cout<<"a[1]:"<<a[1]<<endl;
	cout<<"a[2]:"<<a[2]<<endl;
	cout<<"a[3]:"<<a[3]<<endl;
	cout<<"a[4]:"<<a[4]<<endl;
	cout<<"a[5]:"<<a[5]<<endl;
	cout<<"a[6]:"<<a[6]<<endl;
	cout<<"a[7]:"<<a[7]<<endl;
	cout<<"a[8]:"<<a[8]<<endl;
        cout<<"a:"<<a<<endl;
	cout<<"========================"<<endl;
	strcpy(a,b);
	cout<<"strcpy(a,b);之后"<<endl;
	cout<<"a[0]:"<<a[0]<<endl;
        cout<<"a[1]:"<<a[1]<<endl;
        cout<<"a[2]:"<<a[2]<<endl;
        cout<<"a[3]:"<<a[3]<<endl;
        cout<<"a[4]:"<<a[4]<<endl;
        cout<<"a[5]:"<<a[5]<<endl;
        cout<<"a[6]:"<<a[6]<<endl;
        cout<<"a[7]:"<<a[7]<<endl;
        cout<<"a[8]:"<<a[8]<<endl;
        cout<<"a:"<<a<<endl;
	cout<<a[5]<<endl;
	return 0;
}

//输出：
/*******************
a[0]:a
a[1]:b
a[2]:c
a[3]:d
a[4]:e
a[5]:f
a[6]:
a[7]:
a[8]:
a:abcdef
========================
strcpy(a,b);之后
a[0]:A
a[1]:B
a[2]:C
a[3]:
a[4]:e
a[5]:f
a[6]:
a[7]:
a[8]:
a:ABC
f
******************/
/*

这个程序原本a中的数据是 "abcdef\0", b中的数据是"ABC\0"  strcpy(a,b); 把b中的字符串复制到a中, 所以a变成了"ABC\0ef\0" 所以你输出a[5], 就是f
*/