user-0 提问: 求助。

回复:
user: user-1
content: Both scanf and wscanf return the number of fields successfully converted and assigned; the return value does not include fields that were read but not assigned. A return value of 0 indicates that no fields were assigned. The return value is EOF for an error or if the end-of-file character or the end-of-string character is encountered in the first attempt to read a character.   Format Specification Fields: scanf and wscanf Functions A format specification has the following form:  % [width] [{h | l | I64 | L}]type  The format argument specifies the interpretation of the input and can contain one or more of the following:   White-space characters: blank (' '); tab ('\t'); or newline ('\n'). A white-space character causes scanf to read, but not store, all consecutive white-space characters in the input up to the next non–white-space character. One white-space character in the format matches any number (including 0) and combination of white-space characters in the input.   Non–white-space characters, except for the percent sign (%). A non–white-space character causes scanf to read, but not store, a matching non–white-space character. If the next character in stdin does not match, scanf terminates.   Format specifications, introduced by the percent sign (%). A format specification causes scanf to read and convert characters in the input into values of a specified type. The value is assigned to an argument in the argument list.  The format is read from left to right. Characters outside format specifications are expected to match the sequence of characters in stdin; the matching characters in stdin are scanned but not stored. If a character in stdin conflicts with the format specification, scanf terminates, and the character is left in stdin as if it had not been read.  When the first format specification is encountered, the value of the first input field is converted according to this specification and stored in the location that is specified by the first argument. The second format specification causes the second input field to be converted and stored in the second argument, and so on through the end of the format string.  An input field is defined as all characters up to the first white-space character (space, tab, or newline), or up to the first character that cannot be converted according to the format specification, or until the field width (if specified) is reached. If there are too many arguments for the given specifications, the extra arguments are evaluated but ignored. The results are unpredictable if there are not enough arguments for the format specification.  Each field of the format specification is a single character or a number signifying a particular format option. The type character, which appears after the last optional format field, determines whether the input field is interpreted as a character, a string, or a number.   The simplest format specification contains only the percent sign and a type character (for example, %s). If a percent sign (%) is followed by a character that has no meaning as a format-control character, that character and the following characters (up to the next percent sign) are treated as an ordinary sequence of characters, that is, a sequence of characters that must match the input. For example, to specify that a percent-sign character is to be input, use %%.  An asterisk (*) following the percent sign suppresses assignment of the next input field, which is interpreted as a field of the specified type. The field is scanned but not stored.

user: user-2
content: scanf("%d",&a); 这个这个~~~

user: user-3

user: user-4
content: 恩，scanf()语法是这样规定的，可以加一个非法输入语句控制就可以了，我编译了的，可以跑      #include <stdio.h>  int main() { 	int a=0; 	char ch; 	 	scanf("%d",&a); 	 	for(;a==0;) 	{	 		while ((ch = getchar()) != '\n') 			continue; 		scanf("%d",&a); 	} 	 	printf("%d",a); }

user: user-5
content: scanf("%d",&n); 应当输入数字，如果输入字母，scanf 语句执行失败。 int n; int flag; flag = scanf("%d",&n); if  (flag== 1) printf("good\n"); else printf("bad\n");  flag = scanf("%d",&n); 送返成功读入的数据个数。输入字母，flag 得0，n 原有值不变。  你的情况，由于输入流里的你输入的字母 没有被清掉，后面的输入语句连续执行失败。可以用 fflush(stdin);  清除 多余的东西。