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When and why will a compiler initialise memory to 0xCD, 0xDD, etc. on malloc/free/new/delete?
...EDEDED) would give an inaccessible address under 3gb.
*/
static unsigned char _bNoMansLandFill = 0xFD; /* fill no-man's land with this */
static unsigned char _bAlignLandFill = 0xED; /* fill no-man's land for aligned routines */
static unsigned char _bDeadLandFill = 0xDD; /* fill free obj...
Test whether string is a valid integer
...sonably elegant) way of doing this - I don't want to have to pick it apart char by char.
11 Answers
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How to read data when some numbers contain commas as thousand separator?
...thod using the setAs function like so:
setClass("num.with.commas")
setAs("character", "num.with.commas",
function(from) as.numeric(gsub(",", "", from) ) )
Then run read.csv like:
DF <- read.csv('your.file.here',
colClasses=c('num.with.commas','factor','character','numeric','num.w...
How to convert a byte array to a hex string in Java?
...ly this answer, this is the function I currently use:
private static final char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();
public static String bytesToHex(byte[] bytes) {
char[] hexChars = new char[bytes.length * 2];
for (int j = 0; j < bytes.length; j++) {
int v = bytes[j] &...
Convert line-endings for whole directory tree (Git)
...laces line endings and properly handles whitespace, quotes, and shell meta chars.
find . -type f -exec dos2unix {} \;
If you're using dos2unix 6.0 binary files will be ignored.
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Regex match everything after question mark?
... have to use the "dot all" modifier to allow the dot to match the new line character. Whether or not you have to do this, and how to do this, depends on the language you are using. It appears that you forgot to mention the programming language you are using in your question.
Another alternative tha...
How do I read an entire file into a std::string in C++?
...os_type fileSize = ifs.tellg();
ifs.seekg(0, ios::beg);
vector<char> bytes(fileSize);
ifs.read(bytes.data(), fileSize);
return string(bytes.data(), fileSize);
}
This solution resulted in about 20% faster execution times than the other answers presented here, when taking the...
Efficient way to determine number of digits in an integer
...cialization optimization for 8-bit numbers
template <>
int numDigits(char n)
{
// if you have the time, replace this with a static initialization to avoid
// the initial overhead & unnecessary branch
static char x[256] = {0};
if (x[0] == 0) {
for (char c = 1; c != 0...
Rails ActionMailer - format sender and recipient name/email address
...e the name and email, you can end up with an invalid From header by simply concatenating strings. Here is a safe way:
require 'mail'
address = Mail::Address.new email # ex: "john@example.com"
address.display_name = name.dup # ex: "John Doe"
# Set the From or Reply-To header to the following:
addr...
What reason is there to use null instead of undefined in JavaScript?
...eed to make different falsy checks. It would not be the last time that you concat a null object to a string and get a "null" as a string. Or passing a 0 as numeric value and wondering why the IF statement handles is t as a false.
– com2ghz
Feb 11 '16 at 9:29
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