我尝试使用此网站上的代码(how-do-you-allow-spaces-to-be-entered-using-scanf)
char name[15]; //or char*name=malloc(15);
/* Ask user for name. */
printf("What is your name? ");
/* Get the name, with size limit. */
fgets(name, MAX, stdin);
/* Remove trailing newline, if there. */
if ((strlen(name) > 0) && (name[strlen(name) - 1] == '\n'))
name[strlen(name) - 1] = '\0';
/* Say hello. */
printf("Hello %s. Nice to meet you.\n", name);
当我在main中运行此代码时,它的效果非常好。输出是:
What is your name? j k rowling
Hello j k rowling. Nice to meet you.
但是,当我将此代码放入while循环或切换开关时:
char name[15];
switch (choice) {
case 1:
printf("What is your name? ");
/* Get the name, with size limit. */
fgets(name, MAX, stdin);
/* Remove trailing newline, if there. */
if ((strlen(name) > 0) && (name[strlen(name) - 1] == '\n'))
name[strlen(name) - 1] = '\0';
/* Say hello. */
printf("Hello %s. Nice to meet you.\n", name);
break; }
输出结果为:
What is your name? Hello . Nice to meet you.
所以,它不会等到输入一个字符串。也许fgets不起作用我不知道。
如何使此代码生效?或者使用所有空格从输入获取字符串的任何替代方法。我试过这个:
switch (choice) {
case 1:
printf("What is your name? ");
scanf("%[^\n]s", name);
printf("%s\n", name); }
输出是:
What is your name? ╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠╠
这些有什么问题?我使用visiual studio。我总是遇到麻烦。这是关于它的吗?
答案 0 :(得分:1)
问题是stdin
未正确刷新。
您需要手动刷新它。 ( fflush()功能可用。但它有问题。)
以下是解决您的问题的示例代码。见working here:
#include <stdio.h>
#define MAX 15
int main(void) {
// your code goes here
char name[MAX];
char c;
int choice=1;
while(choice>0 && choice<3)
{
printf("Enter your choice: ");
scanf("%d", &choice);
switch(choice)
{
case 1:
//Flush stdin
while ((c = getchar()) == '\n');
ungetc(c, stdin);
printf("What is your name? ");
fgets(name, MAX, stdin);
if ((strlen(name) > 0) && (name[strlen(name) - 1] == '\n'))
name[strlen(name) - 1] = '\0';
printf("Hello %s. Nice to meet you.\n", name);
break;
case 2:
printf("Your choice is case 2\n");
break;
}
}
return 0;
}