我有一个我正在使用的程序（安静简单）需要用户使用scanf输入。这些值存储在struct数组中。无论如何，我认为我正确地将所有语法都记录下来（如果我不能纠正我），但每当我想要printf来查看结果时，我都没有从ID [i] .Middle_Name中获取值。由于我不明白的原因，它似乎是空的。我试图添加一个print语句来尝试调试它但仍然没有。也许我错过了什么？
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
struct Students{
char First_Name[20];
char Last_Name[20];
char Middle_Name[20];
int Age;
};
int main(void){
int n = 0; //number of students
int i = 0; //counter
printf("Please enter the total number of students in your class: ");
scanf("%d", &n);
struct Students ID[n];
printf("\n");
printf("******************** \n");
printf("After entering student info, they are displayed in full_name/middle_name/age order. \n");
printf("******************** \n");
for(i = 1; i <= n; i++){
printf("Please enter the first name of student with ID: %d \t", i);
scanf("%s", (ID[i].First_Name));
printf("\n");
printf("Please enter the last name of student with ID: %d \t", i);
scanf("%s", (ID[i].Last_Name));
printf("\n");
printf("Please enter the middle name of student ID: %d \t", i);
scanf("%s", (ID[i].Middle_Name));
printf("\n");
printf("Please enter the age of student ID: %d \t", i);
scanf("%d", &(ID[i].Age));
printf("\n");
}
printf("In your class, we have: \n");
printf("%s", ID[1].Middle_Name);
for(i = 1; i <= n; i++){
printf("%s \t", ID[i].First_Name);
printf("%s \t", ID[i].Last_Name);
printf("%s \t", ID[i].Middle_Name);
printf("%d \n", ID[i].Age);
}
return(0);
}
答案 0 :(得分：1)
您必须从i = 0而不是i = 1开始才能获得数组的第一个元素。您应该将i <= n替换为i < n。
for(i = 0; i < n; i++)
{
...
}
答案 1 :(得分：0)
我建议用gets替换scanf（＆＃34;％s＆＃34;，id [i] ....） 例如。
gets(ID[i].Middle_Name);
并且从循环中的0开始而不是1
for（i = 0; i＆lt; n; i ++） { ..... }
答案 2 :(得分：0)
for(i = 0; i <= n; i++)
{
//Your input code
}
for(i = 0; i <= n; i++)
{
// your output code
}
答案 3 :(得分：-1)
代码中的语法错误
struct Students ID[n];
数组长度必须是常量数字，或者您可以像这样使用new
struct Students *ID = new struct Students[n];
答案 4 :(得分：-1)
// <-- note leading ' ' on all format strings
// <-- always check returned value from input statements
// <-- following line would try to access past end of array,
// arrays start with offset of 0,
// for(i = 1; i <= n; i++)
#include <stdio.h>
#include <stdlib.h>
//#include <string.h>
//#include <stdarg.h>
struct Students
{
char First_Name[20];
char Last_Name[20];
char Middle_Name[20];
int Age;
};
int main(void){
int n = 0; //number of students
int i = 0; //counter
printf("Please enter the total number of students in your class: ");
if( 1 != scanf(" %d", &n) )
{
perror( "scanf failed reading num students" );
exit( EXIT_FAILURE );
}
struct Students ID[n];
printf("\n");
printf("******************** \n");
printf("After entering student info, they are displayed in full_name/middle_name/age order. \n");
printf("******************** \n\n");
for( i=0; i< n; i++ )
{
printf("Please enter the first name of student with ID: %d \t", i+1);
if( 1 != scanf(" %s", (ID[i].First_Name)) )
{
perror( "scanf failed for first name" );
exit( EXIT_FAILURE );
}
printf("\n");
printf("Please enter the last name of student with ID: %d \t", i+1);
if( 1 != scanf(" %s", (ID[i].Last_Name)) ) // <-- check returned value
{
perror( "scanf failed for last name" );
exit( EXIT_FAILURE );
}
printf("\n");
printf("Please enter the middle name of student ID: %d \t", i+1);
if( 1 != scanf(" %s", (ID[i].Middle_Name)) ) // <-- check returned value
{
perror( "scanf failed for middle name" );
exit( EXIT_FAILURE );
}
printf("\n");
printf("Please enter the age of student ID: %d \t", i+1);
if( 1 != scanf(" %d", &(ID[i].Age)) ) // <-- check returned value
{
perror( "scanf failed for student age" );
exit( EXIT_FAILURE );
}
printf("\n");
} // end while
printf("In your class, we have: \n");
printf("%s", ID[1].Middle_Name);
// <-- following line would try to access past end of array, arrays start with offset of 0, not 1
//for(i = 1; i <= n; i++)
for( i=0; i<n; i++ )
{
printf("%s \t", ID[i].First_Name);
printf("%s \t", ID[i].Last_Name);
printf("%s \t", ID[i].Middle_Name);
printf("%d \n", ID[i].Age);
printf("\n"); // put each student on a new line
} // end for
return(0);
}