大约有 22,000 项符合查询结果（耗时：0.0298秒） [XML]
How to append rows to an R data frame
...<- function(n){
df <- data.frame(x = numeric(n), y = character(n), stringsAsFactors = FALSE)
for(i in 1:n){
df$x[i] <- i
df$y[i] <- toString(i)
}
df
}
Here's a similar approach, but one where the data.frame is created as the last step.
# Use preallocated vectors
f4 <...
Convert timestamp in milliseconds to string formatted time in Java
...ormat("HH:mm:ss.SSS");
formatter.setTimeZone(TimeZone.getTimeZone("UTC"));
String dateFormatted = formatter.format(date);
See SimpleDateFormat for a description of other format strings that the class accepts.
See runnable example using input of 1200 ms.
...
OceanBase使用libeasy原理源码分析：服务器端 - 数据库(内核) - 清泛网 - ...
... 得到easy_request_t中成员request_list_node的指针
(type *)( (char *)__mptr - offsetof(type,member) );}) // 指针减去 request_list_node成员在easy_request_t中的偏移就得到了easy_request_t的首地址
其中offsetof(type,member)是得到member这个这个...
How to strip all whitespace from string
How do I strip all the spaces in a python string? For example, I want a string like strip my spaces to be turned into stripmyspaces , but I cannot seem to accomplish that with strip() :
...
Can a Byte[] Array be written to a file in C#?
...le to a file."
The path of least resistance would be:
File.WriteAllBytes(string path, byte[] bytes)
Documented here:
System.IO.File.WriteAllBytes - MSDN
share
|
improve this answer
...
How to display long messages in logcat
...
If logcat is capping the length at 1000 then you can split the string you want to log with String.subString() and log it in pieces. For example:
int maxLogSize = 1000;
for(int i = 0; i <= veryLongString.length() / maxLogSize; i++) {
int start = i * maxLogSize;
int end = (i+1...
Changing variable names in Vim
...nvar()
expand("<cword>") gets the word under the cursor. The search string uses % for file-scope, and the \(\W\) patterns look for non-word characters at the boundary of the word to replace, and save them in variables \1 and \2 so as to be re-inserted in the replacement pattern.
...
What are free monads?
...gives you a way to "get out" of it.
More generally, if X is a Y with some extra stuff P, then a "free X" is a a way of getting from a Y to an X without gaining anything extra.
Examples: a monoid (X) is a set (Y) with extra structure (P) that basically says it has an operation (you can think of add...
How to drop SQL default constraint without knowing its name?
... drop the constraint and dynamically execute it.
declare @schema_name nvarchar(256)
declare @table_name nvarchar(256)
declare @col_name nvarchar(256)
declare @Command nvarchar(1000)
set @schema_name = N'MySchema'
set @table_name = N'Department'
set @col_name = N'ModifiedDate'
select @Command = '...
Fastest way to reset every value of std::vector to 0
...ATIONS = 100000;
const size_t TEST_ARRAY_SIZE = 10000;
int main(int argc, char** argv) {
std::vector<int> v(TEST_ARRAY_SIZE, 0);
for(size_t i = 0; i < TEST_ITERATIONS; ++i) {
#if TEST_METHOD == 1
memset(&v[0], 0, v.size() * sizeof v[0]);
#elif TEST_METHOD == 2
...