printf, sprintf print at least two decimal places - formatting

Question

I'm trying to figure out how to use sprintf to print at least two decimal places and no leading zeros. For instance
input:
23
23.0
23.5
23.55
23.555
23.0000
output:
23.00
23.00
23.50
23.55
23.555
23.00
any formatting help would be appreciated

Answer 1

There is no such built-in format specifier. You could check if the number to be printed has two or fewer decimals (round to two decimals and compare), and if so use %.02f. If the number has more decimals, use a %g specifier. Here's an example in Ruby:
def print_two_dec(number)
rounded = (number*100).to_i / 100.0
if number == rounded
printf "%.02f\n", number
else
printf "%g\n", number
end
end
[ 23, 23.0, 23.5, 23.55, 23.555 ].each do |number|
print_two_dec(number)
end
Outputs:
23.00
23.00
23.50
23.55
23.555

Answer 2

in PHP you could use
<?php
$number = 0.56;
echo sprintf("%0.2f",$number);

Answer 3

In PHP, you may use the number_format function for this purpose, too, which also allows you to change delimiters.

Answer 4

In php this is what I did (inspired by this post). Maybe not the most elegant but... I made a function for printing numbers as strings. I wanted to be able to have flexibility so I have a couple of parameters.
PHP:
function print_num($num,$numdec,$atleast = false,$max_dec = -1)
{
$ret_norm = false;
if (!$atleast)
$ret_norm = true;
else //atleast = true
{
//Want at least $numdec decimals
//Do we have two or fewer and want to return two or fewer?
if ($num == ((int)($num*100)/100) & $numdec <= 2 )
$ret_norm = true;
else
{
//See if we have enough dec. already
$just_dec = substr((string)$num,strpos((string)$num,".") + 1);
if ($numdec >= strlen($just_dec))
$ret_norm = true;
else
{
//More decimals than at least value - make sure we don't go over max if set
if ( $max_dec >= 0 && strlen($just_dec) > $max_dec )
{
//Confine to max_dec length
$ret_norm = true;
$numdec = $max_dec; //Set for sprintf below
$num = number_format($num,$max_dec); //Round the value so doesn't just chop off
}
else if ($max_dec >= 0)
$ret_norm = false;
} //else
} //else
} //else atlest
if ($ret_norm)
return sprintf("%0.".$numdec."f",$num);
else
return sprintf("%s",$num); //print as is
} //print_num
And to call the function (to have at least two decimals but max 4:
print_num($mynum,2,true,4);
If the number is 34.1, you get 34.10
If the number is 34.12345 you get 34.1235
etc.

Answer 5

Does "23.555".toFixed(2) not do what I think it does? (Javascript)