处理用户的输入

Question

当我输入一个浮点数（例如48.3）时，显示的结果是48.00而不是48.30。每当我尝试输入空格的字符串时，程序立即结束。我需要帮助，如何解决这个问题？

 int integer;
 char a[50];

 float fnum;
 char b[50];


 printf("Please enter an integer : ");
 scanf("%s",&a);

 integer = atoi(a);

 printf("\nPlease enter a floating-point number : ");
 scanf("%s", &b);

 fnum = atoi(b);

 printf("Output : \n");

 printf("%i + %.2f = %.2f \n", integer,fnum,(integer+fnum));
 printf("%i - %.2f = %.2f \n", integer,fnum,(integer-fnum));
 printf("%i * %.2f = %.2f \n", integer,fnum,(integer*fnum));

Answer 1

您正在通过调用b将字符串atoi转换为整数。您想将其转换为浮点数，因此请使用atof：

fnum = atof(b);

Answer 2

atoi返回一个int。 atof返回一个浮点数。

int integer;
char a[50];

float fnum;
char b[50];


printf("Please enter an integer : ");
scanf("%s",&a);

integer = atoi(a);

printf("\nPlease enter a floating-point number : ");
scanf("%s", &b);

fnum = atof(b);

printf("Output : \n");

printf("%d + %.2f = %.2f \n", integer,fnum,(integer+fnum));
printf("%d - %.2f = %.2f \n", integer,fnum,(integer-fnum));
printf("%d * %.2f = %.2f \n", integer,fnum,(integer*fnum));