[RESOLVED] working with substr and addition

moboter

I have a string that has a value of H2010002
with the substring i only grab the last 3 characters 002
$max=substr ( $row[1], 5 );
now if I add 1 to the $max it drops the leading zeroes
$newmax=$max+1

is there a solution
or is there a better function i could use

bradgrafelman

You could use [man]printf/man to output the number with zero-padding, e.g.:

$myVar = 3;

printf("%03d", $myVar); // outputs: 003

Ashley_Sheridan

The zero tells PHP that it's a string, right up until you perform math on it when it converts it to a number and drops leading zeros.

If you need that leading zero kept, you'll have to add it after either manually, or like bradgrafelman said by using the printf/sprintf functions.

bradgrafelman

Ashley Sheridan;10945214 wrote:
The zero tells PHP that it's a string

Well, it's technically a string simply because that is the variable type that [man]substr/man returns.

As you pointed out, however, "variable types" mean very little in PHP (as compared to a more strictly-typed language, e.g. C/C++) since it will pretty much convert between types as necessary.

The only reason I suggested using [man]printf/man (or, similarly, [man]sprintf/man) is that the zero's seemed to be strictly for display/formatting purposes, thus it would be appropriate to use a function that modifies how the data is displayed/formatted rather than trying to finagle the data itself back into what it "looked" like before.

moboter

finally found a function as you gave me the keyword I couldnt think of
zeroes were not just for displaying in one form but in several others as well.
The function was

str_pad($max+1, 3, "00", STR_PAD_LEFT

thanks to you all

bradgrafelman

I would think the same thing could be done with:

$newmax = sprintf("&#37;03d", $max+1);

Either way, glad you found a solution.