FileMaker While Function

How It Works

The format of a while function is broken into four parts: initial variables, the condition, logic, and the results. The function repeats the logic section until the condition is false; that is how the function provides the ability to loop. In the example below the While function returns a list of numbers 1 through 5:

While ( 
    [ 
     count = 1; 
     numberList = "" 
    ]; 
    count < 6 ; 
    [
     numberList = numberList & (count) & "¶"; 
     count = count + 1 
    ]; 
numberList 
)

The function returns:

1
2
3
4
5

Notes

• Initial variables are available throughout the loop of the function.
• You can define multiple initial variables by enclosing them in brackets, similar to how let functions work.
• Variables that need to retain information from each iteration must be defined in the initial variable section otherwise their values are empty in the next iteration.
• To prevent infinite loops the while function will return "?" after the number of iterations exceeds a limit.
• The default limit is 50,000 iterations. Use the new function, Set Recursion, to set a new limit to the number of iterations.

Conclusion

With the advent of the While function, development of FileMaker applications will become a simpler and quicker process, eliminating the need for one-off recursive functions. Download the demo file to try out the new function.