PHP printf()Function
Examples
Output formatted string:
$number = 9;
$str = "Beijing";
printf("There are %u million bicycles in %s.",$number,$str);
?>
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Definition and Usage
The printf() function outputs a formatted string.
The arg1, arg2, ++ parameters will be inserted into the main string at percent (%) signs. This function is executed step by step. At the first % sign, arg1 is inserted, at the second % sign, arg2 is inserted, and so on.
Note:If there are more % signs than arg parameters, you must use placeholders. A placeholder is inserted after the % sign and consists of a number and "\$". See example 2.
Tip:Related functions:sprintf()、 vprintf()、 vsprintf()、 fprintf()andvfprintf()
Syntax
| Parameters | Description |
|---|---|
| format | Required. Specifies the string and how to format the variables within it. Possible format values:
Additional format values. Must be placed between % and the letter (e.g. %.2f):
Note:If multiple of the above format values are used, they must be used in the order shown above, without mixing them up. |
| arg1 | Required. Specifies the parameter to be inserted at the first % sign in the format string. |
| arg2 | Optional. Specifies the parameter to be inserted at the second % sign in the format string. |
| arg++ | Optional. Specifies the parameters to be inserted at the third, fourth, etc. % signs in the format string. |
Technical Details
| Return value: | Returns the length of the outputted string. |
|---|---|
| PHP Version: | 4+ |
More Examples
Example 2
Using placeholders:
$number = 123;
printf("With 2 decimals: %1$.2f
<br>With no decimals: %1$u",$number);
?>
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Example 3
Demonstration of all possible format values:
$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)
?>
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Example 4
Demonstration of string specifiers:
$str1 = "Hello";
$str2 = "Hello world!";
printf("[%s]<br>",$str1);
printf("[%8s]<br>",$str1);
printf("[%-8s]<br>",$str1);
printf("[%08s]<br>",$str1);
printf("[%'*8s]<br>",$str1);
printf("[%8.8s]<br>",$str2);
?>
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PHP String Reference Manual Other Extensions