w3resource

PHP: vfprintf() function

Description

The vfprintf() function writes a formatted string to a stream.

Version:

(PHP 5)

Syntax:

vfprintf (file_handle, format, array_args)

Parameters:

Name Description Required /
Optional		 Type
file_handle When a file is successfully opened by fopen() or fsockopen() it returns a resource ID, which is referred as file handler or file pointer. Required Resource
format Each conversion specification starts with a single percent sign (%) and ends with the following conversion characters.
% - returns a percent sign.
b - the argument is treated as an integer and display it as a binary number.
c - the argument is treated as an integer and display it as a ASCII value.
d - the argument is treated as an integer and display as a signed decimal number.
e - the argument is treated as scientific notation (e.g. 1.2e+2).
E - the argument treated as scientific notation (e.g.1.2E+2).
u - the argument is treated as an integer, and display as an unsigned decimal number.
f- the argument is treated as a float, and display as a floating-point number. (local aware)
F - the argument is treated as a float, and display as a floating-point number (non-locale aware).
g - shorter of %e and %f.
G - shorter of %E and %f.
o- the argument is treated as an integer, and display as an octal number.
s - the argument is treated as string and display as a string.
x - the argument is treated as an integer and display as a hexadecimal number (with lowercase letters).
X - the argument is treated as an integer and display as a hexadecimal number (with uppercase letters).

Optional specification :
Sign specifier : display a sign (+ or -) in front a number. By default a - sign is used in front of a number if it is negative.

Padding character :
Default character is space. An alternate padding character can be specified by prefixing it with a single quote.
Alignment specifier. : - character makes the alignment left-justified. The default is right justified.
Width specifier : An integer number specifies the width of the field.
Precision specifier : The argument specify how many decimal number should be displayed for floating numbers. When using this specifier on a string, it acts as a cutoff point, setting a maximum character limit to the string. 		Required String
array_args Display array values as a formatted string according to the specified format. Required Array

Return value:

The length of the outputted string.

Value Type : Integer

Example of php vfprintf() function

<?php
$string1 = 'My Roll No. is :';
$roll_no = 22;
$file_handler = fopen('testvf.txt','w');
vfprintf($file_handler, '%s   %u', array($string1, $roll_no));
fclose($file_handler);
// Let open the file file once again and read the content.
$file_name = 'testvf.txt';
$file_handler = fopen($file_name, 'r');
$file_data = fread($file_handler, 1024);
fclose($file_handler);
echo ($file_data);
?>

Output:

My Roll No. is :   22

View the example in the browser

See also

PHP Function Reference

Previous: ucwords
Next: vprintf



PHP: Tips of the Day

PHP: Pass a PHP string to a JavaScript variable (and escape newlines)

<script>
  var myvar = <?php echo json_encode($myVarValue); ?>;
</script>

Using json_encode() requires:

  • PHP 5.2.0 or greater
  • $myVarValue encoded as UTF-8 (or US-ASCII, of course)

Since UTF-8 supports full Unicode, it should be safe to convert on the fly.

Note that because json_encode escapes forward slashes, even a string that contains </script> will be escaped safely for printing with a script block.

Ref : https://bit.ly/34f0Dym