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What does “dereferencing” a pointer mean?
...he pointer may be relative to some specific memory area, which the CPU may select based on CPU "segment" registers or some manner of segment id encoded in the bit-pattern, and/or looking in different places depending on the machine code instructions using the address.
For example, an int* properly ...
How to change the CHARACTER SET (and COLLATION) throughout a database?
...re schema to utf8. Hope this helps!
-- Change DATABASE Default Collation
SELECT DISTINCT concat('ALTER DATABASE `', TABLE_SCHEMA, '` CHARACTER SET utf8 COLLATE utf8_unicode_ci;')
from information_schema.tables
where TABLE_SCHEMA like 'database_name';
-- Change TABLE Collation / Char Set
SELECT...
How to convert a char array back to a string?
I have a char array:
15 Answers
15
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What is cardinality in MySQL?
...ow cardinality column with only 2 possible values as the index will not be selective enough to be used.
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Get contentEditable caret index position
...tion(editableDiv) {
var caretPos = 0,
sel, range;
if (window.getSelection) {
sel = window.getSelection();
if (sel.rangeCount) {
range = sel.getRangeAt(0);
if (range.commonAncestorContainer.parentNode == editableDiv) {
caretPos = range.endOffset;
}
...
Get string character by index - Java
I know how to work out the index of a certain character or number in a string, but is there any predefined method I can use to give me the character at the nth position? So in the string "foo", if I asked for the character with index 0 it would return "f".
...
Conveniently Declaring Compile-Time Strings in C++
...y cumbersome, as the string needs to be declared as a variadic sequence of characters, e.g.
15 Answers
...
What is the difference between an int and a long in C++?
...
The only guarantee you have are:
sizeof(char) == 1
sizeof(char) <= sizeof(short) <= sizeof(int) <= sizeof(long) <= sizeof(long long)
// FROM @KTC. The C++ standard also has:
sizeof(signed char) == 1
sizeof(unsigned char) == 1
// NOTE: These size are...
Length of string in bash
...NG=C LC_ALL=C
bytlen=${#myvar}
LANG=$oLang LC_ALL=$oLcAll
printf "%s is %d char len, but %d bytes len.\n" "${myvar}" $chrlen $bytlen
will render:
Généralités is 11 char len, but 14 bytes len.
you could even have a look at stored chars:
myvar='Généralités'
chrlen=${#myvar}
oLang=$LANG oLc...
PostgreSQL Crosstab Query
... - not fit for missing attributes
crosstab(text) with 1 input parameter:
SELECT *
FROM crosstab(
'SELECT section, status, ct
FROM tbl
ORDER BY 1,2' -- needs to be "ORDER BY 1,2" here
) AS ct ("Section" text, "Active" int, "Inactive" int);
Returns:
Section | Active | Inacti...