I am trying to print out a double that is always 4 digits as well as has 2 decimal places.
For example, If the number was 105.456789
my String.Format would print out 0105.45
I understand that %.2f allows for the two decimal place problem.
I also understand that %04d allows for the 4 digit problem
However, I cannot for the life of me figure out how to combine the two.
I have tried doing a double String.format
I have tried doing one String.format and using both %04d and %.2f
System.out.println(String.format("Gross Pay: $%.2f %04d", 105.456789));
I expect the output to be 0105.45 but I can't even get it to compile
Two things: first of all, your code does compile. But it immediately fails at runtime:
Exception in thread "main" java.util.MissingFormatArgumentException: Format specifier '%04d'
Because: you are using two patterns in your format spec, but provide only one value.
Yes, %.2f %04d that are two specs, not one.
( Please let that sink in: there is a distinct difference between compile time errors and runtime exceptions. And it is important to understand that difference. )
Back to the "real" problem. Instead of using two patterns for one value, you have to thus use one spec, like:
System.out.println(String.format("Gross Pay: $%07.2f", 105.456789));
Gross Pay: $0105.46
The "trick": that number in front of the "dot" needs to account for the overall desired length. Overall, you want: 4 digits+dot+2 digits, resulting in 7 chars. And 0 to fill upfront.
Thus your spec needs to start with "07".