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Why does C# disallow readonly local variables?
...into the CLR/CLI initonly opcode. This flag can only be applied to fields and has no meaning for a local. In fact, applying it to a local will likely produce unverifiable code.
This doesn't mean that C# couldn't do this. But it would give two different meanings to the same language construct. T...
How to use a dot “.” to access members of dictionary?
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Recommend adding getstate and setstate so that deep copy and other systems can support it.
– user1363990
Sep 27 '17 at 3:01
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Why doesn't a python dict.update() return the object?
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Python's mostly implementing a pragmatically tinged flavor of command-query separation: mutators return None (with pragmatically induced exceptions such as pop;-) so they can't possibly be confused with accessors (and in the same vein, assignment is not an expression, the statement-expressi...
PHP Pass variable to next page
...you use something like sessions, cookies or GET / POST variables. Sessions and cookies are quite easy to use, with session being by far more secure than cookies. More secure, but not completely secure.
Session:
//On page 1
$_SESSION['varname'] = $var_value;
//On page 2
$var_value = $_SESSION['var...
Can I query MongoDB ObjectId by date?
... an ObjectId embedded with a given datetime */
/* Accepts both Date object and string input */
function objectIdWithTimestamp(timestamp) {
/* Convert string date to Date object (otherwise assume timestamp is a date) */
if (typeof(timestamp) == 'string') {
timestamp = new Date(timest...
Extract substring using regexp in plain bash
I'm trying to extract the time from a string using bash, and I'm having a hard time figuring it out.
4 Answers
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Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
...r connection; role, port, password, ... See:
Run batch file with psql command without password
The same cannot be called with psql -c "SELECT ...\gexec" since \gexec is a psql meta‑command and the -c option expects a single command for which the manual states:
command must be either a command s...
What generates the “text file busy” message in Unix?
... Use lsof to check what other processes are using it. You can use kill command to kill it if needed.
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How to find serial number of Android device?
I need to use a unique ID for an Android app and I thought the serial number for the device would be a good candidate. How do I retrieve the serial number of an Android device in my app ?
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What does 'low in coupling and high in cohesion' mean
I have problems understanding the statement low in coupling and high in cohesion . I have googled and read a lot about this, but still finding it hard to understand.
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