printf()

printf() — Output a formatted string.

Built-in function of PHP 8.5. The manual lists it as available in PHP 4, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.

Signature

printf(string $format, mixed ...$values): int

Parameters

Parameter	Type	What it takes
$format	string	An integer followed by a dollar sign $, to specify which number argument to treat in the conversion.
...$values	mixed

Return value

Returns the length of the outputted string.

Example

A runnable snippet:

$n = 43951789; $u = -43951789; $c = 65; // ASCII 65 is 'A' // notice the double %%, this prints a literal '%' character printf("%%b = '%b'\n", $n); // binary representation printf("%%c = '%c'\n", $c); // print the ascii character, same as chr() function printf("%%d = '%d'\n", $n); // standard integer representation printf("%%e = '%e'\n", $n); // scientific notation printf("%%u = '%u'\n", $n); // unsigned integer representation of a positive integer printf("%%u = '%u'\n", $u); // unsigned integer representation of a negative integer printf("%%f = '%f'\n", $n); // floating point representation printf("%%o = '%o'\n", $n); // octal representation printf("%%s = '%s'\n", $n); // string representation printf("%%x = '%x'\n", $n); // hexadecimal representation (lower-case) printf("%%X = '%X'\n", $n); // hexadecimal representation (upper-case) printf("%%+d = '%+d'\n", $n); // sign specifier on a positive integer printf("%%+d = '%+d'\n", $u); // sign specifier on a negative integer

Output:

%b = '10100111101010011010101101' %c = 'A' %d = '43951789' %e = '4.39518e+7' %u = '43951789' %u = '4251015507' %f = '43951789.000000' %o = '247523255' %s = '43951789' %x = '29ea6ad' %X = '29EA6AD' %+d = '+43951789' %+d = '-43951789'

Changelog

Version	Change
8.5.0	A formatter that does not specify a precision now correctly treats it as a precision of 0, instead of incorrectly resetting the precision.
8.0.0	This function no longer returns false on failure.
8.0.0	Throws a ValueError if the number of arguments is zero; previously this function emitted an E_WARNING instead.
8.0.0	Throws a ValueError if [width] is less than zero or bigger than PHP_INT_MAX; previously this function emitted an E_WARNING instead.
8.0.0	Throws a ValueError if [precision] is less than zero or bigger than PHP_INT_MAX; previously this function emitted an E_WARNING instead.
8.0.0	Throws an ArgumentCountError when fewer arguments are given than required; previously this function emitted an E_WARNING instead.