函数.txt

钱能主编 C++程序设计教程（第一版） 该书习题的答案代码

//*************************
//**      ch5_1.cpp      **
//*************************

#include <iostream.h>

int func1();
int func2();

void main()
{
	func1();
	cout<<func2()<<endl;
}

int func1()
{
	int n=12345;
	return n;
}

int func2()
{
	int m;
	return m;
}

//*************************
//**      ch5_2.cpp      **
//*************************

#include <iostream.h>

void func();

int n=1;

void main()
{
	static int a;
	int b=-10;
	cout<<"In main()"<<endl
		<<"a: "<<a<<","
		<<"b: "<<b<<","
		<<"n: "<<n<<endl;

	b+=4;
	func();

	cout<<"In main() again"<<endl
		<<"a: "<<a<<","
		<<"b: "<<b<<","
		<<"n: "<<n<<endl;

	n+=10;
	func();
}

void func()
{
	static int a=2;
	int b=5;

	a+=2;
	b+=5;
	n+=12;
	
	cout<<"In fucn()"<<endl
		<<"a: "<<a<<","
		<<"b: "<<b<<","
		<<"n: "<<n<<endl;
}

递归函数定义；
long fact(int n)
{
	if(n==1)
		return 1;
	return fact(n-1)*n;
}

long fib(int n)  //斐波那契数列第n项
{
	if(n>2)
		return (fib(n-1)+fib(n-2));
	else
		return 1;
}

using of inline:
#include <iostream.h>

inline int isnumber(char);

void main()
{
	char c;
	while((c=cin.get())!='\n')
	{
		if(isnumber(c))
			cout<<"you enter a digit."<<endl;
		else
			cout<<"you enter a non-digit."<<endl;
	}
}

inline int isnumber(char ch)
{
	return (ch>='0' && ch<='9')?1:0;
}