Question

I have a code like :

def a = 2111 - 1112
//which calculates a as 999.

But in the above result i need a to be as 0999, i.e i need the leading zeros in the a. How i can do this?

Answer 1

Seems like there should be a much Groovy-er solution, but this the best I could come up with:

Integer.metaClass.sub = {
    def padTo = Math.max(delegate.toString().length(), it.toString().length())
    return (delegate - it).toString().padLeft(padTo, '0')
}

println 2111.sub(1112)

I doubt you want to actually change the behavior of the “-” operator, but if you do, I think it’d be better if you changed String’s metaClass.subtract instead and used “2111” – “1112”