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+--- Thread: variable name characters allowed. (/thread-9495.html)
variable name characters allowed. - webmasterpdx - 11-15-2017 11:50 AM
Is there a way to know what characters can be used in a variable name and also as the first character in the name. e.g. V_1 is a valid variable name, but _V1 is not. Also, there are "other" characters from the Char key that are allowed, but I don't know how to tell which ones are valid. e.g. %1 is valid, but $1 is not. Likewise some of the odder characters like the w omega character is valid, and others are not. I test them by trying them out.
Anyway, if anyone knows whats valid in the name and also what is valid for the first character...please let me know.
Note that while I can use regular alpha chars, I was thinking there might be uses in obfuscation for those who want to protect their program code.
RE: variable name characters allowed. - Joe Horn - 11-15-2017 02:48 PM
The HP Prime User Guide says this: "The name of a variable must be a sequence of alphanumeric characters (letters and numbers), starting with a letter. Names are case-sensitive, so the variables named MaxTemp and maxTemp are different."
RE: variable name characters allowed. - webmasterpdx - 11-15-2017 06:47 PM
Yet %1 is not alpha numeric and there are other weird characters that are not alphanum, like a zeta with a circle at the center....from the Char button.
RE: variable name characters allowed. - DrD - 11-15-2017 06:52 PM
%1 doesn't work in [CAS].
RE: variable name characters allowed. - webmasterpdx - 11-15-2017 07:10 PM
That's interesting. I can do %1:=1 in Home, but not in CAS and when defined in Home, to try to read %1 in CAS doesn't work, but it does in HOME.
RE: variable name characters allowed. - cyrille de brébisson - 11-16-2017 05:52 AM
Hello,
Here is the code that identifies an identifier (var names and the like)
Code:
Int FindEndOfValidIdentifier(wchar_t const *s, wchar_t DecSeparator)
{
if (DecSeparator==L'\0') DecSeparator= Calc->DecSeparator();
wchar_t const *S= s;
if (*s==L'\uE003' || (*s==L'\u03c0' && s[1]<128)) return 1; // complex i, pi with non unicode after...
if ((*s<L'A' || (*s>L'Z' && *s<=L'_') || (*s>L'z' && *s<128) || *s==L'\u25b6') && *s!=L'%') return 0; s++;
while (((*s>=L'A' && *s<=L'Z') || *s==L'_' || (*s>=L'a' && *s<=L'z') || (*s>=L'0' && *s<=L'9') || *s>=128) && // In 7 bit ascii, only allows 0-9, A-Z, a-z.
!(*s==L'\u25B6' || *s==L'\uE004' || // Above 128, disable, Sto -1
*s==L'\u2212' || *s==L'\u00b2' || *s==L'\u221a' || *s==L'\u2264' || *s==L'\u2260' || *s==L'\u2265')) // neg(-) ° sqrt <= # >=
s++;
return s-S;
}Cyrille[/code]
RE: variable name characters allowed. - webmasterpdx - 11-16-2017 06:13 AM
Ah, interesting....of course! It's unicode. I forgot about that. Thanks Cyrille.
-Donald