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Best way to serialize an NSData into a hexadeximal string
... string of NSData. Empty string if data is empty. */
const unsigned char *dataBuffer = (const unsigned char *)[self bytes];
if (!dataBuffer)
return [NSString string];
NSUInteger dataLength = [self length];
NSMutableString *hexString = [NSMutableString stri...
PHP: How to remove all non printable characters in a string?
I imagine I need to remove chars 0-31 and 127,
17 Answers
17
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Which MySQL datatype to use for an IP address? [duplicate]
...nvert them:
INSERT INTO `table` (`ipv4`) VALUES (INET_ATON("127.0.0.1"));
SELECT INET_NTOA(`ipv4`) FROM `table`;
For IPv6 addresses you could use a BINARY instead:
`ipv6` BINARY(16)
And use PHP’s inet_pton and inet_ntop for conversion:
'INSERT INTO `table` (`ipv6`) VALUES ("'.mysqli_real_es...
Test if characters are in a string
...
Use the grepl function
grepl(value, chars, fixed = TRUE)
# TRUE
Use ?grepl to find out more.
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Select something that has more/less than x character
Was wondering if it's possible to select something that has more/less than x characters in SQL.
4 Answers
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How do I lowercase a string in C?
...ent such a function. So yes, just loop through the string and convert each character to lowercase.
Something trivial like this:
#include <ctype.h>
for(int i = 0; str[i]; i++){
str[i] = tolower(str[i]);
}
or if you prefer one liners, then you can use this one by J.F. Sebastian:
for ( ;...
Random alpha-numeric string in JavaScript? [duplicate]
...
If you only want to allow specific characters, you could also do it like this:
function randomString(length, chars) {
var result = '';
for (var i = length; i > 0; --i) result += chars[Math.floor(Math.random() * chars.length)];
return result;
}
...
Using backticks around field names
...backticks, I would assume it lets you get away with ridiculous stuff like
SELECT `id`, `my name`, `another field` , `field,with,comma`
Which does of course generate badly named tables.
If you're just being concise I don't see a problem with it,
you'll note if you run your query as such
EXPLA...
What is array to pointer decay?
...n explicit pointer to that array" - this is incorrect. If a is an array of char, then a is of type char[N], and will decay to char*; but &a is of type char(*)[N], and will not decay.
– Pavel Minaev
Sep 22 '09 at 19:39
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How can I pad an int with leading zeros when using cout
...) << 25;
}
the output will be
00025
setfill is set to the space character (' ') by default. setw sets the width of the field to be printed, and that's it.
If you are interested in knowing how the to format output streams in general, I wrote an answer for another question, hope it is us...