While loop

[Edgar Goldemer]

Hey Statalists,

haven´t found anything about this topic, so I hope you can help me out.


If I use a command such as:

while var1 > 0 {
....
....
change var1
}

Does Stata check whether at least one value of the column var1 is bigger than zero or does it check the first value or..?

I´m asking because the code I use stopped although some of the values in the column the while command referred to have still been bigger than zero.

[Edgar Goldemer]

I answered it myself - while does check the first observation

[Nick Cox]

I rarely write while loops but when I do they often look something like this:

local worktodo = 1

while `worktodo' {
    quietly count if var1 > 0
    if r(N) == 0  local worktodo = 0
    else {
          * code to work more at the problem
    }
}