c - 使用c中的指针初始化结构的构造函数值
问题描述
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
struct Person {
char name[50];
int year_of_birth;
char sex[7];
char father[50];
char mother[50];
char significant_other[50];
char children[50];
};
struct Person* person_constructor(char *name, int year_of_birth, char *sex);
int main(){
struct Person* p1 = person_constructor("Abbas", 1970, "male");
}
struct Person* person_constructor(char *name, int year_of_birth, char *sex) {
struct Person *p;
printf("%s",*name);
printf("%s",*sex);
printf("%d",&year_of_birth);
// how to initalise these here and return name, age and sex everytime , can you tell me in print function
}
我想做: Person* person_constructor(char *name, int year_of_birth, char *sex); 具有给定参数的人并将其返回。还要分配内存。
解决方案
在下面的示例代码中,您可以找到问题的可能解决方案之一。在 C 语言中不可能返回一个以上的变量,但是您可以返回指向构造结构对象的指针并使用符号 stuct_ptr->struct_member 访问结构成员。
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
struct Person {
char name[50];
int year_of_birth;
char sex[7];
char father[50];
char mother[50];
char significant_other[50];
char children[50];
};
struct Person* person_constructor(char *name, int year_of_birth, char *sex);
int main(){
struct Person* p1 = person_constructor("Abbas", 1970, "male");
/* it is not possible to return more variables in C */
/* you can use pointer to access members from constructed structure: */
printf("print from main:\n %s %d %s \n", p1->name, p1->year_of_birth, p1->sex);
if( p1 != NULL) free(p1); /* do not forget do deallocate something taht is allocated */
return 0;
}
struct Person* person_constructor(char *name, int year_of_birth, char *sex) {
struct Person *p = calloc(1, sizeof(struct Person));
if( p == NULL ) return p; /* memory alocation failed! */
strcpy(p->name, name);
p->year_of_birth = year_of_birth;
strcpy(p->sex, sex);
printf("print from constructor:\n");
printf("%s ",p->name);
printf("%s ",p->sex);
printf("%d \n",p->year_of_birth);
return p;
}