How to format an f32 with a specific precision and prepended zeros?

Question

What format string should I use in the println! macro in order to print 0.0 as 00000.000?

println!("={:05.3}", 0.0);

Output: =0.000

Expected: =00000.000

Answer 1

The first number (after the zero) is the total number of characters.

So you do display your number with 5 characters. If you want to have 5 numbers before the dot, you must type:

println!("{:09.3}", 123.45);

Output: 00123.450

Because 9 minus 3 minus the dot = 5 digits.