How can I print number in 4 digit?

Question

I want to print a list of numbers in php.
But I want to print 4 digits of numbers (preceding with zero if necessary), eg
0001, 0009, 0076, 0129, 1234

What should I do?

Answer 1

printf("%04d", $num);

Answer 2

printf ('%04d' ,$num)

Answer 3

的printf

Answer 4

Look at the PHP Language Reference Manual and search for zero-padded integers

The link gives the sprintf details, but the format string information applies to related functions like printf