Literal values that include quotes

Saturday 26 October 2019 @ 12:25 am

I was recently working on a formula that had the crystal syntax for “is one of”.  It looked something like this:

{LastName} in [ "Smith","Jones","Thompson","Rutledge","Harris" ]

Each value goes in quotes (single or double). You separate the values with a comma and you put square brackets around the list. So I was surprised today when I saw that the formula was actually like this:

{LastName} in [ "Smith""Jones","Thompson","Rutledge","Harris" ]

Notice the comma missing between the first two values.  The report had been running for months without error messages which I didn’t understand, so I started testing.  My experiments pointed me to a syntax rule that I had read about but never used. It is for when your formula includes a literal string that you surround with double quotes, and when the literal string itself contains double quotes.  Crystal would assume the first quote is the ‘open’ and the second one is the close, even when you want the second one to be part of the visible output.   One solution is to use two consecutive double quotes within the literal. Whenever Crystal finds two consecutive double quotes within a literal surrounded by a pair of double quotes, Crystal will interpret the consecutive quotes as one literal quote and not as a closing quote.  This is much easier to explain with an example.  So if I wanted a formula to output this string:

The syntax for "is one of" uses brackets

I could write it like this inside the Crystal formula:

"The syntax for ""is one of"" uses square brackets"

The formula engine would only display one of the two consecutive double quotes in each pair.  That explains why my formula with the missing comma doesn’t generate an error.  Crystal treated the consecutive double quotes as a single literal and then combined the first two elements in the list as being the single value:

Smith"Jones

There was no error message, but the results would not have been correct.

BTW, the same principle applies to single quotes. If you put two consecutive single quotes in a string surrounded by single quotes, Crystal will ignore the first and treat the second as a literal quote.

The reason I didn’t think of this right away is that I have never used consecutive quotes in a formula. If I have a string that needs to contain single quotes I surround it with double quotes. And if the string needs to contain double quotes I surround it with single quotes. In the rare case that a string needs both I would split it into separate pieces and combine them. I find that using consecutive quote pairs makes the formula harder to follow.

(For examples of my most popular formulas, please visit the FORMULAS page on my website.)







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Jeff-Net
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