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标题: vprintf() 函数用法 [打印本页]

作者: xiexie    时间: 2008-10-22 22:46     标题: vprintf() 函数用法

The vprintf() function outputs a formatted string. vprintf()函数的作用是:输出格式化字符串。 Unlike printf(), the arguments in vprintf(), are placed in an array. The array elements will be inserted at the percent (%) signs in the main string. This function works "step-by-step". At the first % sign, the first array element is inserted, at the second % sign, the second array element is inserted, etc. 与fprintf()函数不同,vprintf()函数中的自变量是位于数组中的,数组元素的字符串之前都要加上百分号(%)。这个函数是“一步一步[step-by-step]”按顺序执行。在第一个%后,将插入第一个数组元素;在第二个%后,将插入第二个数组元素,依次类推。 Parameter参数 Description描述 format Required. Specifies the string and how to format the variables in it. 必要参数。指定字符串,以及如何定义其中变量的格式。 Possible format values: 可能值如下: %% - Returns a percent sign %% -返回百分号 %b - Binary number %b ?返回二进制数 %c - The character according to the ASCII value %c ?返回与ASCII值相对应的字符 %d - Signed decimal number %d ?带有正负号的十进制数 %e - Scientific notation (e.g. 1.2e+2) %e ?科学计数符号(如:1.2e+2) %u - Unsigned decimal number %u ?不带正负号的十进制数 %f - Floating-point number (local settings aware) %f ? 浮点数据(本地设置) %F - Floating-point number (not local settings aware) %F ?浮点数据(非本地设置) %o - Octal number %o ?十进制数 %s - String %s ?字符串 %x - Hexadecimal number (lowercase letters) %x ?十六进制数(小写字母) %X - Hexadecimal number (uppercase letters) %X ?十六进制数(大写字母) Additional format values. These are placed between the % and the letter (example %.2f): 其它格式的值。它是位于%和字母之间的(如:%.2f) + (Forces both + and - in front of numbers. By default, only negative numbers are marked) +(在数字前加上+和-;默认情况下,只有负数是被标记出来的) ' (Specifies what to use as padding. Default is space. Must be used together with the width specifier. Example: %'x20s (this uses "x" as padding) ’(指定使用什么作为补白,默认值是空格。它必须与宽度指定器一起使用。如:%'x20s(使用“x”作为padding)) - (Left-justifies the variable value) - (左调整变量值) [0-9] (Specifies the minimum width held of to the variable value) [0-9](指定变量值的最小宽度) .[0-9] (Specifies the number of decimal digits or maximum string length) .[0-9](指定十进制数值或最大字符串长度) Note: If multiple additional format values are used, they must be in the same order as above. 注意:如果使用附加格式值,那么它必须与上述顺序相同 argarray Required. An array with arguments to be inserted at the % signs in the format string 必要参数。指定在格式化字符串中插在%之后的带有自变量的数组对象 -------------------------------------------------------------------------------- Tips and Notes 提示和注意点 Note: If there are more % signs than arguments, you must use placeholders. A placeholder is inserted after the % sign, and consists of the argument- number and "/$". See example three. 注意:注意:如果这里的%比自变量更多,你必须使用占位符[placeholders]。占位符是安插在%之后的,它是由自变量-数字和“/$”组成的。具体可以见案例3。 Tip: Related functions: fprintf(), printf(), sprintf(), vfprintf(), and vsprintf(). 提示:相关函数:printf(), sprintf(), vfprintf(), vprintf(), 和 vsprintf() -------------------------------------------------------------------------------- Example 1 案例1 The output of the code above will be: 上述代码将输出下面的结果: Hello world. Day number 123 -------------------------------------------------------------------------------- Example 2 案例2 The output of the code above will be: 上述代码将输出下面的结果: 123.000000456.000000 -------------------------------------------------------------------------------- Example 3 案例3 Use of placeholders: 使用占位符: With no decimals: %1/$u",array($number));?> The output of the code above will be: 上述代码将输出下面的结果: With 2 decimals: 123.00 With no decimals: 123




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