14.18 程式設計練習.4

主要是是練習把結構傳遞給函式引數的兩種形式：傳遞結構整體本身；傳遞結構指標指向的成員值。

//向函式傳遞結構資訊，一是傳遞整個結構本身，二是利用結構指標傳遞結構成員。
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define MAX 40

struct info
{
	char firstname[MAX];
	char middlename[MAX];
	char lastname[MAX];
};

struct member
{
	char num[20];//用字元陣列儲存賬號，防止用int or double型會溢位資料。
	struct info info_full;//結構巢狀。
};

void print(const struct member [],int);//使用結構陣列的函式。即傳遞給函式的是結構陣列!!!
void print_p(char *,char *,char *,char *);//利用指標，傳遞結構的值。

int main(void)
{
	struct member member_array[5];
	int count=0;

	puts("Enter the infomation of person:");
	puts("Enter the first name:");
	while(count<5 && gets(member_array[count].info_full.firstname)!=NULL && member_array[count].info_full.firstname[0]!='\0')
	{
		puts("Enter the middle name:");
		gets(member_array[count].info_full.middlename);
		puts("Enter the last name:");
		gets(member_array[count].info_full.lastname);
		puts("Enter the social number:");
		scanf("%s",&member_array[count].num);
		count++;
		while(getchar()!='\n')
			continue;
		if(count<5)
			puts("Enter the next first name:");
	}

	puts("Print out by trans parameter:");
	print(member_array,count);

	puts("Another print out by pointer toward value:");
	for(int index=0;index<count;index++)
		print_p(member_array[index].info_full.firstname,member_array[index].info_full.middlename,member_array[index].info_full.lastname,member_array[index].num);

	return 0;
}

void print(const struct member member_array[],int count)
{
	printf("Here is the list of infomation:\n");
	for(int index=0;index<count;index++)
		if(member_array[index].info_full.middlename[0]=='\0')
			printf("%s %c %s -%s\n",member_array[index].info_full.firstname,member_array[index].info_full.middlename[0],member_array[index].info_full.lastname,member_array[index].num);
		else
		    printf("%s %c. %s -%s\n",member_array[index].info_full.firstname,member_array[index].info_full.middlename[0],member_array[index].info_full.lastname,member_array[index].num);
}

void print_p(char *a,char *b,char *c,char *n)
{
	if(b[0]=='\0')
	    printf("%s %c %s -%s\n",a,' ',c,n);
	else
		printf("%s %c. %s -%s\n",a,b[0],c,n);
}




//C實現允許把結構作為引數傳遞，或把指向結構的指標作為引數傳遞。
//如果只關心結構的一部分，還可以將結構成員作為引數傳遞給函式。