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How do I show the value of a #define at compile-time?
...ment with the argument enclosed in double quotes. Thus:
#define STR(x) #x
char *s1 = "abc";
char *s2 = STR(abc);
will assign identical values to s1 and s2. If you run gcc -E you can see this in the output. Perhaps STR would be better named something like ENQUOTE.
This solves the problem of putti...
Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?
...n multiple courses, books, and jobs, I have seen text fields defined as VARCHAR(255) as kind of the default for "shortish" text. Is there any good reason that a length of 255 is chosen so often, other than being a nice round number ? Is it a holdout from some time in the past when there was a goo...
How to cast/convert pointer to reference in C++
... bhhaaa, I added the "I guess" because it made me write at least 30 chars. that's also way I add the "..........."
– Roee Gavirel
Apr 16 '12 at 11:41
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Variable declaration placement in C
...declare all of your variables at the beginning of a scope block.
So, your char c declaration is valid as it is at the top of the for loop scope block. But, the char *s declaration should be an error.
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What is the difference between cout, cerr, clog of iostream header in c++? When to use which one?
...minal is historically slow (terminals or consoles are still slow), writing character by character is ineffective, writing a chunk of bytes is much more effective.
– Some programmer dude
Apr 4 '18 at 17:23
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List of standard lengths for database fields
...ize for names in your
database. In particular, do not assume that a four-character
Japanese name in UTF-8 will fit in four bytes – you are likely to
actually need 12.
https://www.w3.org/International/questions/qa-personal-names
For database fields, VARCHAR(255) is a safe default choic...
Const before or const after?
...to constant pointer. Brilliant. And finally it explains why I can do const char as well as char const.
– Vit Bernatik
Mar 10 '17 at 17:48
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Hidden features of C
...
Multi-character constants:
int x = 'ABCD';
This sets x to 0x41424344 (or 0x44434241, depending on architecture).
EDIT: This technique is not portable, especially if you serialize the int.
However, it can be extremely useful to ...
What is a good Hash Function?
... that differ only in the last 4 bytes can collide easily. If you have a 30 character string, that differ in the last 4 bytes, after 28 bytes have been processes, the hashes differ only in the last 2 bytes. That means you are GUARANTEED a collision for one of the remaining two-byte values. (Yeah, it'...
No visible cause for “Unexpected token ILLEGAL”
...e error is raised if, for example, you try to run a js file with a rogue @ character, a misplaced curly brace, bracket, "smart quotes", single quotes not enclosed properly (e.g. this.run('dev1)) and so on.
A lot of different situations can cause this error. But if you don't have any obvious syntax ...