I am studying about printf,sprintf and i didnt understand few points, if can some one please help me understand thos points,
At This Link at PHP Manual:
There are explanations are numbered from one to six:
What i didnt understand is: The First and The Second(1(sign specifier), 2(padding specifier)), if can some one please help me with example for thos i will be very thankful.
The sign specifier forces a sign, even if it's positive. So, if you have
$x = 10;
$y = -10;
printf("%+d", $x);
printf("%+d", $y);
You'll get:
+10
-10
The padding specifier adds left padding so that the output always takes a set number of spaces, which allows you to align a stack of numbers, useful when generating reports with totals, etc.
$x = 1;
$y = 10;
$z = 100;
printf("%3d\n", $x);
printf("%3d\n", $y);
printf("%3d\n", $z);
You'll get:
1
10
100
If you prefix the padding specifier with a zero, the strings will be zero padded instead of space padded:
$x = 1;
$y = 10;
$z = 100;
printf("%03d\n", $x);
printf("%03d\n", $y);
printf("%03d\n", $z);
Gives:
001
010
100
PRE tags.
The sign specifier: Placing a plus sign ( + ) forces negative AND positive signs to be visible (only negative values are specified by default).
$n = 1;
$format = 'With sign %+d without %d';
printf($format, $n, $n);
Prints:
With sign +1 without 1
The padding specifier says what character will be used to pad the result to the specified length. The character is specified by prefixing it with a single quote ('). For example to pad to length 3 with the character 'a':
$n = 1;
$format = "Padded with 'a' %'a3d"; printf($format, $n, $n);
printf($format, $n, $n);
Prints:
Padded with 'a' aa1
1.Sign specifier:
By default browsers only display - sign in front of negative numbers. + sign in front of positive numbers are omitted. But it is possible to instruct the browser to display + sign in front of positive numbers by using sign specifier. For example:
$num1=10;
$num2=-10;
$output=sprintf("%d",$num1);
echo "$output<br>";
$output=sprintf("%d",$num2);
echo "$output";
Output:
10
-10
Here the + sign before the positive number is omitted. However, if we put a + sign after % character of %d then the omission no longer takes place.
$num1=10;
$num2=-10;
$output=sprintf("%+d",$num1);
echo "$output<br>";
$output=sprintf("%+d",$num2);
echo "$output";
Output:
+10
-10
2.Padding specifier:
The padding specifier adds certain number of characters to the left or right of the output. The characters may be empty spaces, zeroes or any other ASCII character.
For example,
$str="hello";
$output=sprintf("[%10s]",$str);
echo $output;
Source code output:
[ hello] //Total length of 10 positions,first five being empty spaces and remaining five being "hello"
HTML output:
[ hello] //HTML displays only one empty space and collapses the rest, you have to use the <pre>...</pre> tag in the code for HTML to preserve the empty spaces.
Putting a negative sign left justifies the output:
$output=["%-10s",$string];
echo $output;
Source code output:
[hello ]
HTML output:
[hello ]
Putting 0 after % sign replaces empty spaces with zeroes.
$str="hello";
$output=sprintf("[%010s]",$str);
echo $output;
Output:
[00000hello]
Left justification
$output=sprintf("[%-010s]",$str);
Output:
[hello00000]
Putting ' followed by any ASCII character like * after % results in the display of that ASCII character instead of empty spaces
$str="hello";
$output=sprintf("[%'*10s]",$str);
echo $output;
Output:
*****hello
Left justification:
$output=sprintf("[%-'*10s]",$str);
echo $output;
Output:
hello*****