Golang: How to pad a number with zeros when printing?

Question

How can I print a number or make a string with zero padding to make it fixed width?

For instance, if I have the number 12 and I want to make it 00

Answer 1

The fmt package can do this for you:

fmt.Printf("|%06d|%6d|\n", 12, 345)

Output:

|000012|   345|

Notice the 0 in %06d, that will make it a width of 6 and pad it with zeros. The second one will pad with spaces.

Try it for yourself here: http://play.golang.org/p/cinDspMccp