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[ function outputs a formatted string. arg1, arg2, ++ parameters will be inserted at the percent (%) signs in the main string. This function works step-by-step. At the first % sign, insert arg1, at the second % sign, insert arg2, and so on. **Note:** If there are more % signs than arg arguments, you must use placeholders. Placeholders are inserted after the % sign and consist of a number and "$". See example 2. **Tip:** Related functions: [sprintf()]( [vprintf()]( [vsprintf()]( [fprintf()]( and [vfprintf()]( * * * ## Syntax printf(_format,arg1,arg2,arg++_) | Parameter | Description | | --- | --- | | _format_ | Required. Specifies the string and how to format the variables in it. Possible format values: * %% - Returns a percent sign % * %b - Binary number * %c - Character corresponding to the ASCII value * %d - Signed decimal number (negative, 0, positive) * %e - Scientific notation using lowercase (e.g., 1.2e+2) * %E - Scientific notation using uppercase (e.g., 1.2E+2) * %u - Unsigned decimal number (greater than or equal to 0) * %f - Floating-point number (local settings aware) * %F - Floating-point number (not local settings aware) * %g - Shorter of %e and %f * %G - Shorter of %E and %f * %o - Octal number * %s - String * %x - Hexadecimal number (lowercase letters) * %X - Hexadecimal number (uppercase letters) Additional format values. Must be placed between the % and the letter (e.g., %.2f): * + (Places a + or - sign in front of a number to define its positivity. By default, only negative numbers are marked, positive numbers are not) * ' (Specifies what to use as padding, default is a space. Must be used with the width specifier. Example: %'x20s (uses "x" as padding)) * - (Left-justifies the variable value) * (Specifies the minimum width of the variable value) * . (Specifies the number of decimal digits or the maximum string length) **Note:** If using multiple format values from the above list, they must be used in the order shown above and cannot be rearranged. | | _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 parameter to be inserted at the third, fourth, etc. % signs in the format string. | ## Technical Details | Return Value: | Returns the length of the output string. | | --- | | PHP Version: | 4+ | * * * ## More Examples ## Example 1 Using the format value %f: [Run Example »]( ## Examplewill affect the lines The instance where placeholders are used: <?php $number = 123; printf("With 2 decimals: %1$.2f
With no decimals: %1$u",$number); ?> [Run Example »]( ## Example 3 Demonstration of all possible format values: <?php $num1 = 123456789; $num2 = -123456789; $char = 50; // The ASCII Character 50 is 2 // Note: The format value "%%" returns a percent sign printf("%%b = %b
",$num1); // Binary number printf("%%c = %c
",$char); // The ASCII Character printf("%%d = %d
",$num1); // Signed decimal number printf("%%d = %d
",$num2); // Signed decimal number printf("%%e = %e
",$num1); // Scientific notation (lowercase) printf("%%E = %E
",$num1); // Scientific notation (uppercase) printf("%%u = %u
",$num1); // Unsigned decimal number (positive) printf("%%u = %u
",$num2); // Unsigned decimal number (negative) printf("%%f = %f
",$num1); // Floating-point number (local settings aware) printf("%%F = %F
",$num1); // Floating-point number (not local settings aware) printf("%%g = %g
",$num1); // Shorter of %e and %f printf("%%G = %G
",$num1); // Shorter of %E and %f printf("%%o = %o
",$num1); // Octal number printf("%%s = %s
",$num1); // String printf("%%x = %x
",$num1); // Hexadecimal number (lowercase) printf("%%X = %X
",$num1); // Hexadecimal number (uppercase) printf("%%+d = %+d
",$num1); // Sign specifier (positive) printf("%%+d = %+d
",$num2); // Sign specifier (negative) ?> [Run Example »]( ## Example 4 Demonstration of string specifiers: <?php $str1 = "Hello"; $str2 = "Hello world!"; printf("[%s]
",$str1); printf("[%8s]
",$str1); printf("[%-8s]
",$str1); printf("[%08s]
",$str1); printf("[%'*8s]
",$str1); printf("[%8.8s]
",$str2); ?> [Run Example »]( * * * [![Image 2: PHP String Reference Manual]( PHP String Reference Manual](