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Re: Single Quotes, Double Quotes [message #11760 is a reply to message #11757]

Thu, 14 May 1998 00:00

davidf
Messages: 2866
Registered: September 1996

Senior Member

Charles Cavanaugh (cavanaug@nicole.eos.ucar.edu) writes:

> Can anyone please explain to me why the line
>
> asciiutc = "1993-09-19T06:30:00.000000Z"
>
> fails compilation with the error message
>
> asciiutc = "1993-09-19T06:30:00.000000Z"
> ^
> % Syntax error.
>
> but the same line, using single quotes instead of double
> quotes, compiles.

I don't know the "official" answer, but I suspect it has
to do with the way octal and hexadecimal numbers are
specified in IDL.

For example, to create a hexadecimal number:

IDL> a = "f4"x
IDL> print, a
244

Or, an octal number 12:

IDL> a = "12
IDL> print,a
10

Thus, if the "thing" you are assigning to a variable
is a number (but you want it as a string), you must use
single quotes or it will be mistaken for a hexadecimal
or octal number. For example, this fails:

IDL> a = "5"
a = "5"
^
% Syntax error.

But this works:

IDL> a = '5'

And this works, because the first thing after the double
quote is a letter:

IDL> a = "A5"

Not sure this "explains" it. But perhaps it illuminates the
problem enough to suggest a solution. :-)

Cheers,

David

-----------------------------------------------------------
David Fanning, Ph.D.
Fanning Software Consulting
E-Mail: davidf@dfanning.com
Phone: 970-221-0438
Coyote's Guide to IDL Programming: http://www.dfanning.com/

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[Message index]

		Re: Single Quotes, Double Quotes By: offenbrg on Mon, 18 May 1998 00:00
		Re: Single Quotes, Double Quotes By: korpela on Thu, 14 May 1998 00:00
		Re: Single Quotes, Double Quotes By: korpela on Thu, 14 May 1998 00:00
		Re: Single Quotes, Double Quotes By: davidf on Thu, 14 May 1998 00:00

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