From Dwayne Wright PMP, PMI-ACP
Certified FileMaker Developer
The Let function can be challenging the first time you encounter it. The Let Function allows you to use your own variables within the syntax of the function. It can be used to make complex calculations easier because you can reference just about anything as a variable. Today I did a quick Let function to parse out the contents between a pair of parenthesis and realized this is a very easy way to explain how a Let function works!
start = Position ( text ; "("; 1; 1)+1;
end = Position ( text ; ")"; 1; 1);
difference = end - start];
Middle ( text; start; difference))
The first variable tells us where the left parenthesis starts (plus one character), the second variable tells us were the right parenthesis ends and the last variables tells us the number of characters between each parenthesis. The position function returns the place where a specified string of text occurs within a search string.
That sets up the last calculation that pulls out the desired data with the Middle function! This function is used to pull a defined number of characters from a text string or field. Unlike the left or right functions, you can define where to start and the number of characters you want to extract. This function is commonly used in text parsing routines, where a large piece of text is broken down and placed into many different fields.
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© 2013 - Dwayne Wright - dwaynewright.com
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