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list.clear() vs list = new ArrayList(); [duplicate]
...olds onto memory, the other one throws out its memory and gets reallocated from scratch (with the default capacity). Which is better depends on whether you want to reduce garbage-collection churn or minimize the current amount of unused memory. Whether the list sticks around long enough to be moved ...
Why is the use of alloca() not considered good practice?
...k rather than on the heap, as in the case of malloc() . So, when I return from the routine the memory is freed. So, actually this solves my problem of freeing up dynamically allocated memory. Freeing of memory allocated through malloc() is a major headache and if somehow missed leads to all sorts...
What are the best practices for catching and re-throwing exceptions?
...
There's a reason I think you've missed from your list here - you may not be able to tell whether you can handle an exception until you've caught it and had a chance to inspect it. For example, a wrapper for a lower-level API that uses error codes (and has zillions...
How to use range-based for() loop with std::map?
...
From this paper: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2049.pdf
for( type-specifier-seq simple-declarator : expression ) statement
is syntactically equivalent to
{
typedef decltype(expression) C;
...
Read whole ASCII file into C++ std::string [duplicate]
...gt;());
Not sure where you're getting the t.open("file.txt", "r") syntax from. As far as I know that's not a method that std::ifstream has. It looks like you've confused it with C's fopen.
Edit: Also note the extra parentheses around the first argument to the string constructor. These are essenti...
How to check if a string in Python is in ASCII?
...f-8, or any other encoding. The source of your string (whether you read it from a file, input from a keyboard, etc.) may have encoded a unicode string in ascii to produce your string, but that's where you need to go for an answer.
Perhaps the question you can ask is: "Is this string the result of e...
How do I install a module globally using npm?
...eral recommendations concerning npm module installation since 1.0rc (taken from blog.nodejs.org):
If you’re installing something that you want to use in your program, using
require('whatever'), then install it
locally, at the root of your
project.
If you’re installing something th...
Actual meaning of 'shell=True' in subprocess
...le where things could go wrong with Shell=True is shown here
>>> from subprocess import call
>>> filename = input("What file would you like to display?\n")
What file would you like to display?
non_existent; rm -rf / # THIS WILL DELETE EVERYTHING IN ROOT PARTITION!!!
>>> c...
Check if a key exists inside a json object
...ws the error error Do not access Object.prototype method 'hasOwnProperty' from target object when using this method. Thoughts?
– hamncheez
Feb 21 '19 at 20:01
2
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How to gzip all files in all sub-directories into one compressed file in bash
... I run
cd ~
tar -cvzf passwd.tar.gz /etc/passwd
tar: Removing leading `/' from member names
/etc/passwd
pwd
/home/myusername
tar -xvzf passwd.tar.gz
this will create
/home/myusername/etc/passwd
unsure if all versions of tar do this:
Removing leading `/' from member names
...