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PHP function vprintf() that outputs formatted strings

黄舟
黄舟Original
2017-11-07 09:11:561337browse

Example

Output a formatted string:

<?php
$number = 9;
$str = "Beijing";
vprintf("There are %u million bicycles in %s.",array($number,$str));
?>

Definition and usage

The vprintf() function outputs a formatted string.

Unlike printf(), the parameters in vprintf() are located in an array. Array elements will be inserted into the main string at the percent sign (%). This function is executed step by step. At the first % sign, the first array element is inserted, at the second % sign, the second array element is inserted, and so on.

Note: If there are more % symbols than arg arguments, you must use placeholders. The placeholder is inserted after the % symbol and consists of a number and "\$". See Example 2.

Tips: Related functions: sprintf(), printf(), vsprintf(), fprintf() and vfprintf()

Syntax

vprintf(format,argarray)
Required. An array with parameters to be inserted into the format string at % symbols.
Parameters Description
format Required. Specifies a string and how to format variables within it.

Possible format values:

  • %% - returns a percent sign %

  • %b - a binary number

  • %c - the character corresponding to the ASCII value

  • %d - the decimal number containing the sign (negative, 0, positive)

  • %e - Use lowercase scientific notation (e.g. 1.2e+2)

  • ##%E - Use uppercase scientific notation (e.g. 1.2E+ 2)

  • %u - Decimal number without sign (greater than or equal to 0)

  • %f - Floating point number (local setting) )

  • %F - floating point number (non-native setting)

  • ##%g - shorter %e and %f
  • %G - shorter %E and %f
  • ##%o - octal number
  • %s - character String
  • %x - Hexadecimal number (lowercase letters)
  • ##%X - Hexadecimal number (uppercase letters)

  • Additional format value. Must be placed between % and a letter (e.g. %.2f):

+ (Add + or - in front of a number to define the sign of the number. By default, only Negative numbers are marked, positive numbers are not marked)

  • ' (Specifies what to use as padding, the default is spaces. It must be used with the width specifier. For example: %'x20s ( Use "x" as padding))

  • - (Adjust the variable value left)

  • [0-9] (Specify the minimum variable value Width)

  • .[0-9] (Specifies the number of decimal places or the maximum string length)

  • Note: If you use more than one of the above The format values ​​must be used in the order above and cannot be disrupted.

argarray

技术细节

返回值: 返回被输出的字符串的长度。
PHP 版本: 4.1.0+

更多实例

实例 1

使用格式值 %f:

<?php
$num1 = 123;
$num2 = 456;
vprintf("%f%f",array($num1,$num2));
?>

实例 2

使用占位符:

<?php
$number = 123;
vprintf("With 2 decimals: %1$.2f
<br>With no decimals: %1$u",array($number));
?>

实例 3

使用 printf() 来演示所有可能的格式值:

<?php
$num1 = 123456789;
$num2 = -123456789;
$char = 50; // The ASCII Character 50 is 2

// Note: The format value "%%" returns a percent sign
printf("%%b = %b <br>",$num1); // Binary number
printf("%%c = %c <br>",$char); // The ASCII Character
printf("%%d = %d <br>",$num1); // Signed decimal number
printf("%%d = %d <br>",$num2); // Signed decimal number
printf("%%e = %e <br>",$num1); // Scientific notation (lowercase)
printf("%%E = %E <br>",$num1); // Scientific notation (uppercase)
printf("%%u = %u <br>",$num1); // Unsigned decimal number (positive)
printf("%%u = %u <br>",$num2); // Unsigned decimal number (negative)
printf("%%f = %f <br>",$num1); // Floating-point number (local settings aware)
printf("%%F = %F <br>",$num1); // Floating-point number (not local settings aware)
printf("%%g = %g <br>",$num1); // Shorter of %e and %f
printf("%%G = %G <br>",$num1); // Shorter of %E and %f
printf("%%o = %o <br>",$num1); // Octal number
printf("%%s = %s <br>",$num1); // String
printf("%%x = %x <br>",$num1); // Hexadecimal number (lowercase)
printf("%%X = %X <br>",$num1); // Hexadecimal number (uppercase)
printf("%%+d = %+d <br>",$num1); // Sign specifier (positive)
printf("%%+d = %+d <br>",$num2); // Sign specifier (negative)
?>

实例 4

字符串说明符的演示:

<?php
$str1 = "Hello";
$str2 = "Hello world!";

vprintf("[%s]<br>",array($str1));
vprintf("[%8s]<br>",array($str1));
vprintf("[%-8s]<br>",array($str1));
vprintf("[%08s]<br>",array($str1)); 
vprintf("[%&#39;*8s]<br>",array($str1));
vprintf("[%8.8s]<br>",array($str2)); 
?>


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