C语言无法输出数组？

Question

我似乎无法在 C 编程中正确输出字符串或整数数组。

我的问题是字符串存储在数组中，我只是无法将它们从数组中取出并输出。

当我手动输入位置(如Array[0])时，它会正确输出。

但是，最终循环无法输出我的任何数组条目。

为什么会发生这种情况？

预先感谢所有回复!

这是代码:

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

main (void)
{
    int memory_start;
    int memory_end;
    int num_jobs;


    printf("Enter the starting memory location to be used : ");
    scanf("%d", &memory_start);

    printf("\nEnter the ending memory location to be used : ");
    scanf("%d", &memory_end);

    printf("\nHow many jobs will be assigned to the memory locations?  \n");
    scanf("%d", &num_jobs);

    int mem_size = memory_end - memory_start;
    int mem_size_init = memory_end - memory_start;
    char names[10][20];
    int  sizes[num_jobs];
    int  mem_st[10];
    int  mem_end[10];
    int x;
    int y;
    int z;
    int temp_size = 0;
    int prev_temp_size;
    char temp_name[20];


    for(x=0; x<num_jobs; x++)
    {
        prev_temp_size = prev_temp_size + temp_size;
        printf("\nEnter the size of the program (size > 0): ");
        scanf("%d", &temp_size);

        if( mem_size >= temp_size && temp_size > 0)
        {
            printf("\nEnter a program name (20 chars): %s", names[1]);
            scanf("%s", &temp_name);

            if(strlen(temp_name) <= 20)
            {
                strcpy(names[x], temp_name);
            //  names[x] = temp_name;
                sizes[x] = temp_size;
                mem_size = mem_size - temp_size;
                mem_st[x] = prev_temp_size + memory_start;
                mem_end[x] = temp_size + mem_st[x];
            }
            else
            {
                printf("\nProgram name is too long. Please re enter data.");
                x--;
            }
        }
        else
        {
            printf("\nMemory Size not supported (not enough space remaining).\nPlease re-enter data with a plausible memory request.");
            printf("\nMemory size remaining: %d", mem_size);
            x--;
        }
    }

    printf("\nYour data is as follows: \n");
    printf("\nYour initial memory size is: %d", mem_size_init);
    printf("\nYour unused memory size is: %d", mem_size);

    for(y=0; y<num_jobs; y++)
    {
        printf("Program: %s", names[y]);
        printf("\n", names[y], " memory size is as follows: \n", "memory start: %d", mem_st[y], "    memory end: %d", mem_end[y]);
    }
}

Answer 1

这是更正后的代码:

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

main (void)
{
 int memory_start;
 int memory_end;
 int num_jobs;

 printf("Enter the starting memory location to be used : ");
 scanf("%d", &memory_start);

 printf("\nEnter the ending memory location to be used : ");
 scanf("%d", &memory_end);

 printf("\nHow many jobs will be assigned to the memory locations? ");
 scanf("%d", &num_jobs);

 int mem_size = memory_end - memory_start;
 int mem_size_init = memory_end - memory_start;
 char names[10][20];
 int  sizes[num_jobs];
 int  mem_st[10];
 int  mem_end[10];
 int x;
 int y;
 int z;
 int temp_size = 0;
 int prev_temp_size;
 char temp_name[20];

 for(x=0; x<num_jobs; x++)
 {
  prev_temp_size = prev_temp_size + temp_size;
  printf("\nEnter the size of the program (size > 0): ");
  scanf("%d", &temp_size);

  if( mem_size >= temp_size && temp_size > 0)
  {
   printf("\nEnter a program name (20 chars): ");
   scanf("%s", temp_name);
   getchar();

   if(strlen(temp_name) <= 20)
   {
    strcpy(names[x], temp_name);
    sizes[x] = temp_size;
    mem_size = mem_size - temp_size;
    mem_st[x] = prev_temp_size + memory_start;
    mem_end[x] = temp_size + mem_st[x];
   }
   else
   {
    printf("\nProgram name is too long. Please re enter data.");
    x--;
   }
  }
  else
  {
   printf("\nMemory Size not supported (not enough space remaining).\nPlease re-enter data with a plausible memory request.");
   printf("\nMemory size remaining: %d", mem_size);
   x--;
  }
 }

 printf("\nYour data is as follows: \n");
 printf("\nYour initial memory size is: %d", mem_size_init);
 printf("\nYour unused memory size is: %d\n", mem_size);

 for(y=0; y<num_jobs; y++)
 {
  printf("\nProgram: %s\n", names[y]);
  printf("\nmemory size is as follows:\nmemory start: %d memory end: %d\n", mem_st[y], mem_end[y]);
 }
}

除了输出格式的变化之外，主要变化是:

• 删除了 scanf("%s", &temp_name); 中的 &，因为数组的名称已经返回对其第一个元素的引用。

• 在 scanf("%s", temp_name); 之后添加了 getchar();，因为读入字符串后会出现额外的 \n 保留在流中，这会导致下一个 scanf 失败。

• 这个:

  printf("\n", names[y], " memory size is as follows: \n", "memory start: %d", mem_st[y], "    memory end: %d", mem_end[y]);    
  

  这不是格式说明符的准备方式，所有变量都需要放在最后，在单个格式说明符字符串之后。