新手求解（写一个程序，打印出每行输入一个字）

[不爱吃酸的大力水手]

#include <stdio.h>
int main(void)
{
int c;
int inspace;

inspace = 0;
while((c = getchar()) != EOF)
{
if(c == ' ' || c == '\t' || c == '\n')
{
if(inspace == 0)
{
inspace = 1;
putchar('\n');
}
/* else, don't print anything */
}
else
{
inspace = 0;
putchar(c);
}
}
return 0;
}
帮我解释一下为什么要这样写，而且if(c == ' ' || c == '\t' || c == '\n')是什么？
while((c = getchar()) != EOF)
{
if(c == ' ' || c == '\t' || c == '\n')
{
if(inspace == 0)
{
inspace = 1;
putchar('\n');
}
/* else, don't print anything */
}
else
{
inspace = 0;
putchar(c);
}

[breakfisher]

帮我解释一下为什么要这样写，而且if(c == ' ' || c == '\t' || c == '\n')是什么？

判断字符'c'是不是空格， space键，换行符

[lilianjie001]

if(c == ' ' || c == '\t' || c == '\n')对你输入的字符进行判断，如果是空格或者回车\t表示 tab键输入，这样的输入就输出换行，否则将输入的字符输出。

[prajna]

if(c == ' ' // space || c == '\t' // tab || c == '\n' //newline )

[zhaoming262350]

if(c == ' ' || c == '\t' || c == '\n') 这个就是判断你输入的字符中，是不是含有‘ ’和‘/t’ 和'\n' 如果有这几个字符就换行， 但是你后面的程序中，只对空格进行了判断，‘\t ’和‘\n’没有相应的程序

[常如意]

判断字符'c'是不是空格， space键，换行符

[大极张三疯]

if(c == ' ' || c == '\t' || c == '\n') 判断输入的字符是否为空格（空白键）、制表符（Tab键）、换行符。 楼主怎么还不结帖呀？

[赵4老师]

C++ Character Constants Character constants are one or more members of the “source character set,” the character set in which a program is written, surrounded by single quotation marks ('). They are used to represent characters in the “execution character set,” the character set on the machine where the program executes. Microsoft Specific For Microsoft C++, the source and execution character sets are both ASCII. END Microsoft Specific There are three kinds of character constants: Normal character constants Multicharacter constants Wide-character constants Note Use wide-character constants in place of multicharacter constants to ensure portability. Character constants are specified as one or more characters enclosed in single quotation marks. For example: char ch = 'x'; // Specify normal character constant. int mbch = 'ab'; // Specify system-dependent // multicharacter constant. wchar_t wcch = L'ab'; // Specify wide-character constant. Note that mbch is of type int. If it were declared as type char, the second byte would not be retained. A multicharacter constant has four meaningful characters; specifying more than four generates an error message. Syntax character-constant : 'c-char-sequence' L'c-char-sequence' c-char-sequence : c-char c-char-sequence c-char c-char : any member of the source character set except the single quotation mark ('), backslash (\), or newline character escape-sequence escape-sequence : simple-escape-sequence octal-escape-sequence hexadecimal-escape-sequence simple-escape-sequence : one of \' \" \? \\ \a \b \f \n \r \t \v octal-escape-sequence : \octal-digit \octal-digit octal-digit \octal-digit octal-digit octal-digit hexadecimal-escape-sequence : \xhexadecimal-digit hexadecimal-escape-sequence hexadecimal-digit Microsoft C++ supports normal, multicharacter, and wide-character constants. Use wide-character constants to specify members of the extended execution character set (for example, to support an international application). Normal character constants have type char, multicharacter constants have type int, and wide-character constants have type wchar_t. (The type wchar_t is defined in the standard include files STDDEF.H, STDLIB.H, and STRING.H. The wide-character functions, however, are prototyped only in STDLIB.H.) The only difference in specification between normal and wide-character constants is that wide-character constants are preceded by the letter L. For example: char schar = 'x'; // Normal character constant wchar_t wchar = L'\x81\x19'; // Wide-character constant Table 1.2 shows reserved or nongraphic characters that are system dependent or not allowed within character constants. These characters should be represented with escape sequences. Table 1.2 C++ Reserved or Nongraphic Characters Character ASCII Representation ASCII Value Escape Sequence Newline NL (LF) 10 or 0x0a \n Horizontal tab HT 9 \t Vertical tab VT 11 or 0x0b \v Backspace BS 8 \b Carriage return CR 13 or 0x0d \r Formfeed FF 12 or 0x0c \f Alert BEL 7 \a Backslash \ 92 or 0x5c \\ Question mark ? 63 or 0x3f \? Single quotation mark ' 39 or 0x27 \' Double quotation mark " 34 or 0x22 \" Octal number ooo — \ooo Hexadecimal number hhh — \xhhh Null character NUL 0 \0 If the character following the backslash does not specify a legal escape sequence, the result is implementation defined. In Microsoft C++, the character following the backslash is taken literally, as though the escape were not present, and a level 1 warning (“unrecognized character escape sequence”) is issued. Octal escape sequences, specified in the form \ooo, consist of a backslash and one, two, or three octal characters. Hexadecimal escape sequences, specified in the form \xhhh, consist of the characters \x followed by a sequence of hexadecimal digits. Unlike octal escape constants, there is no limit on the number of hexadecimal digits in an escape sequence. Octal escape sequences are terminated by the first character that is not an octal digit, or when three characters are seen. For example: wchar_t och = L'\076a'; // Sequence terminates at a char ch = '\233'; // Sequence terminates after 3 characters Similarly, hexadecimal escape sequences terminate at the first character that is not a hexadecimal digit. Because hexadecimal digits include the letters a through f (and A through F), make sure the escape sequence terminates at the intended digit. Because the single quotation mark (') encloses character constants, use the escape sequence \' to represent enclosed single quotation marks. The double quotation mark (") can be represented without an escape sequence. The backslash character (\) is a line-continuation character when placed at the end of a line. If you want a backslash character to appear within a character constant, you must type two backslashes in a row (\\). (SeePhases of Translation in the Preprocessor Reference for more information about line continuation.)

[尖括号]

if(c == ' ' || c == '\t' || c == '\n')这是逻辑语句，||这个符号是或的意思，这语句表示，当输入的字符是空格后者是tab或者是回车的时候结果为真；否则结果为假！