Practice Problem 20

Read it right next to your computer. Book version bitter C

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C language

Basics

Question 1-1

What should a file containing only declarations be called?

Question 1-2

What do you call the files where the actual program is written?

Program Manual

Question 2-1


#include <stdio.h>
#include <string.h>

typedef struct {
    char name[256];
    int age;
    int sex;
} People;

void InputPeople(People* data)
{
    printf("name:");
    scanf("%s", data->name);
    printf("Age:");
    scanf("%d", &data->age);
    printf("Gender(1-Male、2-Woman):");
    scanf("%d", &data->sex);
    printf("\n");
}

void ShowPeople(People data)
{
    char sex[16];

    printf("name:%s\n", data.name);
    printf("Age:%d\n", data.age);

    if (data.sex == 1) {
        strcpy(sex, "Male");
    } else {
        strcpy(sex, "Woman");
    }

    printf("Gender:%s\n", sex);
    printf("\n");
}

Please separate this program into header and source files.

explanatory

Question 3-1

Even though all functions can be written in a single source file and still function, briefly state the reason for deliberately splitting them.

Fundamentals (Answer Key)

Solution 1-1

Header file

Solution 1-2

Source file

Program Documentation (Example Solution)

Include People.h

/* People.h */
#ifndef __PEOPLE_H__
#define __PEOPLE_H__

#include <stdio.h>
#include <string.h>

typedef struct {
    char name[256];
    int age;
    int sex;
} People;

/* Enter your personal data */
extern void InputPeople(People* data);

/* Display personal data */
extern void ShowPeople(People data);

#endif

Solve 2-1 People.c

/* People.c */

#include "People.h"

void InputPeople(People* data)
{
    printf("name:");
    scanf("%s", data->name);
    printf("Age:");
    scanf("%d", &data->age);
    printf("Gender(1-Male、2-Woman):");
    scanf("%d", &data->sex);
    printf("\n");
}

void ShowPeople(People data)
{
    char sex[16];

    printf("name:%s\n", data.name);
    printf("Age:%d\n", data.age);

    if (data.sex == 1) {
        strcpy(sex, "Male");
    } else {
        strcpy(sex, "Woman");
    }

    printf("Gender:%s\n", sex);
    printf("\n");
}

There are various schools of thought on division.
Here, we used the approach of including it within a header file.
It is also possible to perform all #include directives in source files.

Descriptive (answer example)

Solution 4-1

Splitting improves program readability,
making reuse and multi-person development easier.

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Part 0: Program Overview

What is a program?