大约有 40,000 项符合查询结果（耗时：0.0494秒） [XML]
Regex empty string or email
...ex email validation in SO but I did not find any that will accept an empty string. Is this possible through Regex only? Accepting either empty string or email only? I want to have this on Regex only.
...
Android ViewPager with bottom dots
... app:imageResources="@array/img_id_arr"/>
Create an integer array in strings.xml e.g.
<integer-array name="img_id_arr">
<item>@drawable/img1</item>
<item>@drawable/img2</item>
<item>@drawable/img3</item>
<item>@drawable/img4</item&...
Search for executable files using find command
...des. Octal modes are octal numbers (e.g., 111), whereas symbolic modes are strings (e.g., a=x).
Symbolic modes identify the security principals as u (user), g (group) and o (other), or a to refer to all three. Permissions are expressed as x for executable, for instance, and assigned to principals us...
What is the difference between List (of T) and Collection(of T)?
...s that it is returning a new instance. Note that for e.g. a Dictionary<string, List<string>> to return List<string> is just fine, since the dictionary's state only encapsulates the identities of the lists therein, rather than their contents.
– supercat
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What is the maximum value for an int32?
...67,996,680 till 1,867,996,689 of the decimal digits of Pi
The numeric string 2147483647 appears at the 1,867,996,680 decimal digit of Pi. 3.14......86181221809936452346214748364710527835665425671614...
source: http://www.subidiom.com/pi/
...
How to “EXPIRE” the “HSET” child key in redis?
...d zset Redis objects under the hood. Usage example:
RMapCache<Integer, String> map = redisson.getMapCache('map');
map.put(1, 30, TimeUnit.DAYS); // this entry expires in 30 days
This approach is quite useful.
share
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Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...' the matrix.
#'
#' @param data data.frame: input data
#' @param rowtitle string: row-dimension; name of the column in data, which distinct values should be used as row names in the output matrix
#' @param coltitle string: col-dimension; name of the column in data, which distinct values should be u...
How to check if running in Cygwin, Mac or Linux?
...he system information (-s parameter).
Use expr and substr to deal with the string.
Use if elif fi to do the matching job.
You can add more system support if you want, just follow the uname -s specification.
Implementation
#!/usr/bin/env bash
if [ "$(uname)" == "Darwin" ]; then
# Do something...
How can I read a large text file line by line using Java?
...
try (BufferedReader br = new BufferedReader(new FileReader(file))) {
String line;
while ((line = br.readLine()) != null) {
// process the line.
}
}
You can read the data faster if you assume there is no character encoding. e.g. ASCII-7 but it won't make much difference. It is...
Use of Finalize/Dispose method in C#
...
as extra computing effort is needed in the CLR to keep track of classes with active finalizers. - Implementing a finalizer causes this to happen. Calling GC.SuppressFinalize means that the Finalizer should not be called by the r...