I’m looking at Webmonkey’s PHP and MySql Tutorial, Lesson 2. I think it’s a php literal. What does %s
mean? It’s inside the print_f()
function in the while loops in at least the first couple of code blocks.
printf("<tr><td>%s %s</td><td>%s</td></tr>n", ...
with printf or sprintf characters preceded by the % sign are placeholders (or tokens). They will be replaced by a variable passed as an argument.
Example:
$str1 = 'best';
$str2 = 'world';
$say = sprintf('Tivie is the %s in the %s!', $str1, $str2);
echo $say;
This will output:
Tivie is the best in the world!
Note: There are more placeholders (%s for string, %d for dec number, etc…)
Order:
The order in which you pass the arguments counts. If you switch $str1 with $str2 as
$say = sprintf('Tivie is the %s in the %s!', $str2, $str1);
it will print
“Tivie is the world in the best!”
You can, however, change the reading order of arguments like this:
$say = sprintf('Tivie is the %2$s in the %1$s!', $str2, $str1);
which will print the sentence correctly.
Also, keep in mind that PHP is a dynamic language and does not require (or support) explicit type definition. That means it juggles variable types as needed. In sprint it means that if you pass a “string” as argument for a number placeholder (%d), that string will be converted to a number (int, float…) which can have strange results. Here’s an example:
$onevar = 2;
$anothervar = 'pocket';
$say = sprintf('I have %d chocolate(s) in my %d.', $onevar, $anothervar);
echo $say;
this will print
I have 2 chocolate(s) in my 0.
More reading at PHPdocs
Answer:
In printf
, %s
is a placeholder for data that will be inserted into the string. The extra arguments to printf
are the values to be inserted. They get associated with the placeholders positionally: the first placeholder gets the first value, the second the second value, and so on.
Answer:
%s
is a type specifier which will be replaced to valuable’s value (string) in case of %s
.
Besides %s
you can use other specifiers, most popular are below:
d – the argument is treated as an integer, and presented as a (signed) decimal number.
f – the argument is treated as a float, and presented as a floating-point number (locale
aware).
s – the argument is treated as and presented as a string.
Answer:
$num = 5;
$location = 'tree';
$format = 'There are %d monkeys in the %s';
echo sprintf($format, $num, $location);
Will output: “There are 5 monkeys in the tree.”
Answer:
The printf()
or sprintf()
function writes a formatted string to a variable.
Here is the Syntax:
sprintf(format,arg1,arg2,arg++)
format:
- %% – Returns a percent sign
- %b – Binary number
- %c – The character according to the ASCII value
- %d – Signed decimal number (negative, zero or positive)
- %e – Scientific notation using a lowercase (e.g. 1.2e+2)
- %E – Scientific notation using a uppercase (e.g. 1.2E+2)
- %u – Unsigned decimal number (equal to or greater than zero)
- %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)
arg1:
- The argument to be inserted at the first %-sign in the format
string..(Required.)
arg2:
- The argument to be inserted at the second %-sign in the format
string. (Optional)
arg++:
- The argument to be inserted at the third, fourth, etc. %-sign in
the format string (Optional)
Example 1:
$number = 9;
$str = "New York";
$txt = sprintf("There are approximately %u million people in %s.",$number,$str);
echo $txt;
This will output:
There are approximately
9
million people inNew York
.
The arg1, arg2, arg++ parameters will be inserted at percent (%) signs in the main string. This function works “step-by-step”. At the first % sign, arg1 is inserted, at the second % sign, arg2 is inserted, etc.
Note: If there are more % signs than arguments, you must use
placeholders. A placeholder is inserted after the % sign, and consists
of the argument- number and “\$”. Let see another Example:
Example 2
$number = 123;
$txt = sprintf("With 2 decimals: %1$.2f
<br>With no decimals: %1$u",$number);
echo $txt;
This will output:
With 2 decimals:
123.00
With no decimals:123
Another important tip to remember is that:
With
printf()
andsprintf()
functions, escape character is not
backslash ‘\’ but rather ‘%’. Ie. to print ‘%’ character you need to
escape it with itself:
printf('%%%s%%', 'Nigeria Naira');
This will output:
%Nigeria Naira%
Feel free to explore the official PHP Documentation