Getword() and the Countword()

[mxledesma]

 I am doing the Try it exercise of the Formula Tool Can anyone explain to me why

Formula - GetWord([Address], CountWords([Address])-1) within the Formula tool.

I just dont understand why within Countwords the string has Address and a -1. Why -1. If i omit

the -1 it gives a parse error.

[hmdawood]

Because CountWord reflects number of words. Here it means 4 words in the [Address]. 
When I put "-1", it reduces the number to 3.

GetWord counts from 0. So for GetWord to pick the last word it needs to be reduced by 1. Same like function LEFT(), RIGHT() and LEN() combination in excel.