本例中四次输出了a,b的值，但由于格式控制串不同，输出的结果也不相同。第四行的输出语句格式控制串中，两格式串 d 之间加了一个空格(非格式字符)，所以输出的a,b值之间有一个空格。第五行的printf语句格式控制串中加入的是非格式字符逗号， 因此输出

的a,b值之间加了一个逗号。第六行的格式串要求按字符型输出 a,b值。第七行中为了提示输出结果又增加了非格式字符串。

-In this case four times the output of a, b values, but because of the format control string is different from the results of the output is not the same. The fourth line of the output control string in the format statement, the two format string　d a space between the (non-format characters), so the output of a, b there is a space between. The fifth line of the statement printf format string to control the format by adding the non-comma characters, so the output of a, b the value of a comma in between. The sixth line of the format requested by the character string output a, b values. The seventh line of the output results in order to prompt an increase of non-format string.