我正在将程序从普通数组表示法更改为纯指针表示法，并且我无法在 while 循环中使用 getchar() 接收用户输入。我打印出程序正在接收并输出倒置的问号。我不确定为什么会发生这种情况，因为我从未更改过变量类型。问题在于接收用户输入的第二个函数。感谢您的帮助。
#include <stdio.h>
#include <stdlib.h>
/* Function prototypes */
void fillS1(char * x);
void fillS2(char * x, char * y, char z);
void strFilter(char * a, char * b, char c);
int main(int argc, const char * argv[])
{
char s1[42];
char s2[22];
char x = 0;
fillS2(s2, s1, x);
return 0;
}
/* Function to generate a random string of 40 uppercase letters */
void fillS1(char randomlyGeneratedString[])
{
char * pointerToRandom = randomlyGeneratedString;
int i;
for (i = 0; i < 40; i++) {
*(pointerToRandom + i) = 'A' + rand() % 26;
}
pointerToRandom[40] = (char)0;
//printf("This is the generated string %s\n", pointerToRandom);
}
/* Function to get user input of characters */
void fillS2(char userString[], char randomString[], char replacementCharacter)
{
char * pointerToUserString = userString;
char * pointerToRandom = randomString;
int i = 0;
int n = 0;
int capitalLetterCheck = 0;
char loopContinue = 0;
char copyString[42];
char * pointerToCopyString = copyString;
fillS1(pointerToRandom);
do {
/* For loop to copy the first randomly generated string */
for(i = 0; i < 42; i++)
*(pointerToCopyString + i) = *(pointerToRandom + i);
i = 0;
capitalLetterCheck = 0;
/* While loop to to get user input */
printf("Please enter at least 2 capital letters and a maximum of 20.\n");
while (((*(pointerToUserString + i)) = getchar() != '\n')) {
/* Counter to determine how many characters were entered */
i++;
}
i++;
*(pointerToUserString + i) = '\0';
//printf("This is the value if i %i", i);
//printf("This is the user's string %s", pointerToUserString);
/* Capital letter check */
for (n = 0; n < 20; n++) {
if (((*(pointerToUserString + i)) >= 'A') && (*(pointerToUserString + i) <= 'Z'))
{
capitalLetterCheck++;
}
}
if (i < 3) {
printf("You need at least two letters\n");
}
else if (i > 21){
printf("You cannot have more than twenty letters\n");
}
else if (capitalLetterCheck >= 2) {
puts(pointerToUserString);
printf("Enter a character to replace occuring letters.\n");
scanf("%c", &replacementCharacter);
getchar();
strFilter(pointerToCopyString, pointerToUserString, replacementCharacter);
}
else
printf("You must have 2 capital letters.\n");
printf("Would you like to enter another string (y/n)?\n");
loopContinue = getchar();
getchar();
} while (loopContinue != 'n' && loopContinue != 'N');
}
/* Function to replace letters with the character chosen by the user */
void strFilter(char a[], char b[], char c)
{
char * pointerToA = a;
char * pointerToB = b;
int i = 0;
int n = 0;
while (n < 20) {
for (i = 0; i < 40; i++) {
if ((*(pointerToA + i)) == *(pointerToB + n)){
*(pointerToA + i) = c;
}
}
i = 0;
n++;
}
puts(a);
}