如何打印输出以使变量列对齐？

I want to aligning my output in columns. But when I try to do this I always get this:

1. FIRSTNAME1      LASTNAME1 
2. FIRSTNAME2     LASTNAME2
3. FIRSTNAME3    LASTNAME3

The output I want would be like this:

 1. FIRSTNAME1          LASTNAME1   D. 
 2. FIRSTNAME2          LASTNAME2   D.
 3. FIRSTNAME3          LASTNAME3   D.

This is the code that I use:

$log  = $lastname."    ".$firstname.PHP_EOL;

file_put_contents('logs/'.date("Y-m-d").'.txt', $log, FILE_APPEND);

Your names have all different lengths, so if you want your "columns" to be aligned, just concatenating a few spaces won't cut it.

You need to pad that string so that the name + the spaces afterwards always add up to the same number of characters.

Fortunately for you, there is already a function to accomplish that: str_pad.

$log  = strpad($lastname, 16) . ' ' . $firstname . PHP_EOL;

Obviously, you need to choose a padding length that makes sense for your data. Otherwise, any longer $lastname will mess up your desired output.