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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: Using str_replace so that it only acts on the first match?

Can be done with preg_replace: 

function str_replace_first($from, $to, $content)
{
    $from = '/'.preg_quote($from, '/').'/';

    return preg_replace($from, $to, $content, 1);
}

echo str_replace_first('abc', '123', 'abcdef abcdef abcdef'); 
// outputs '123def abcdef abcdef'

The magic is in the optional fourth parameter [Limit]. From the documentation:

[Limit] - The maximum possible replacements for each pattern in each subject string. Defaults to -1 (no limit).

Ref : https://bit.ly/35SCuP8