我目前正在处理C编程类的一个问题,我的程序有点问题。我已经设法编译了这个程序,但显示函数实际上并没有显示列表的内容。这是我的代码:
/**
* Create a structure that has one variable called value and one pointer to the list (making it a
* linked list). Prompt for 5 values from the keyboard as input and store them in the linked list. Print
* out the current contents of the list. Allow the user to add one more value to the linked list, and
* print the contents of the list again.
*/
#include <stdio.h>
struct ValueStore
{
char value[100];
struct ValueStore *nextItem;
};
typedef struct ValueStore ValueStore;
void display(ValueStore *);
int main()
{
printf("This program will ask you for five words or phrases and store them in a list before repeating those integers back to you.n");
printf("You will then be able to add a final value (for a total of six) before the program repeats the list back to you and finishes.n");
/**
* Initialize the first five structs in the list.
*/
char inChar1[100];
char inChar2[100];
char inChar3[100];
char inChar4[100];
char inChar5[100];
printf("Please enter a word or phrase: ");
gets(inChar1);
printf("Please enter a word or phrase: ");
gets(inChar2);
printf("Please enter a word or phrase: ");
gets(inChar3);
printf("Please enter a word or phrase: ");
gets(inChar4);
printf("Please enter a word or phrase: ");
gets(inChar5);
ValueStore fifth = { inChar5 };
ValueStore fourth = { inChar4, &fifth };
ValueStore third = { inChar3, &fourth };
ValueStore second = { inChar2, &third };
ValueStore first = { inChar1, &second };
display(&first); //print out the list starting at first
/*
* add final item to list
*/
char inChar6[100];
printf("Please enter a word or phrase: ");
gets(inChar6);
ValueStore sixth = { inChar6 };
fifth.nextItem = &sixth; //link fifth and sixth together
display(&first);
}
void display(ValueStore *listStart)
{
while(listStart)
{
printf("%sn", listStart->value);
listStart = listStart->nextItem;
}
}
当我尝试运行程序并输入"你好"、"世界"、"什么"、"是"one_answers"向上"来回答提示时,我的显示功能会输出一行�p
并进入下一个输入。我输入最后一个字符串(说"你好"),然后在终端中再次获得�p
。
我知道gets()是不赞成使用fgets()的,但我的指令是明确使用gets((),所以我的手被束缚在那里。
我的gcc编译器是最新的
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.2.1-22ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2)
事实上,编译器在代码中为您提供了很多关于该问题的指示(也称为警告):
test41.c: In function ‘main’:
test41.c:35: warning: initialization makes integer from pointer without a cast
test41.c:36: warning: initialization makes integer from pointer without a cast
test41.c:36: warning: initialization makes integer from pointer without a cast
test41.c:37: warning: initialization makes integer from pointer without a cast
test41.c:37: warning: initialization makes integer from pointer without a cast
test41.c:38: warning: initialization makes integer from pointer without a cast
test41.c:38: warning: initialization makes integer from pointer without a cast
test41.c:39: warning: initialization makes integer from pointer without a cast
test41.c:39: warning: initialization makes integer from pointer without a cast
test41.c:49: warning: initialization makes integer from pointer without a cast
但是,此代码更改将起作用。
#include <stdio.h>
#include <string.h>
struct ValueStore
{
char value[100];
struct ValueStore *nextItem;
};
typedef struct ValueStore ValueStore;
void display(ValueStore *);
int main()
{
printf("This program will ask you for five words or phrases and store them in a list before repeating those integers back to you.n");
printf("You will then be able to add a final value (for a total of six) before the program repeats the list back to you and finishes.n");
/**
* Initialize the first five structs in the list.
*/
char inChar1[100];
char inChar2[100];
char inChar3[100];
char inChar4[100];
char inChar5[100];
printf("Please enter a word or phrase: ");
gets(inChar1);
printf("Please enter a word or phrase: ");
gets(inChar2);
printf("Please enter a word or phrase: ");
gets(inChar3);
printf("Please enter a word or phrase: ");
gets(inChar4);
printf("Please enter a word or phrase: ");
gets(inChar5);
ValueStore fifth;
strcpy(fifth.value, inChar5 );
fifth.nextItem = NULL;
ValueStore fourth;
strcpy(fourth.value, inChar4);
fourth.nextItem = &fifth;
ValueStore third;
strcpy(third.value, inChar3);
third.nextItem = &fourth;
ValueStore second;
strcpy(second.value, inChar2);
second.nextItem = &third;
ValueStore first;
strcpy(first.value, inChar1);
first.nextItem = &second;
display(&first); //print out the list starting at first
/*
* add final item to list
*/
char inChar6[100];
printf("Please enter a word or phrase: ");
gets(inChar6);
ValueStore sixth;
strcpy(sixth.value, inChar6);
sixth.nextItem = NULL;
fifth.nextItem = &sixth; //link fifth and sixth together
display(&first);
}
void display(ValueStore *listStart)
{
while(listStart)
{
printf("%sn", listStart->value);
listStart = listStart->nextItem;
}
}
输出:根据您的问题。
./a.out
This program will ask you for five words or phrases and store them in a list before repeating those integers back to you.
You will then be able to add a final value (for a total of six) before the program repeats the list back to you and finishes.
Please enter a word or phrase: hello
Please enter a word or phrase: world
Please enter a word or phrase: what
Please enter a word or phrase: is
Please enter a word or phrase: up
hello
world
what
is
up
Please enter a word or phrase: to
hello
world
what
is
up
to