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What does @@variable mean in Ruby?
... So if you have a class Vehicle with the class variable @@number_of_wheels then if you create a class Car < Vehicle then it too will have the class variable @@number_of_wheels
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Fastest way to check if a string is JSON in PHP?
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@Bruno If the last decoding works without errors then json_last_error returns JSON_ERROR_NONE.
– Andrea
Feb 14 '18 at 13:50
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What is considered a good response time for a dynamic, personalized web application? [closed]
...ant if the response time is likely to be highly variable, since users will then not know what to expect.
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Rails: Adding an index after adding column
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If you need to create a user_id then it would be a reasonable assumption that you are referencing a user table. In which case the migration shall be:
rails generate migration AddUserRefToProducts user:references
This command will generate the following m...
npm check and update package if needed
...ngle local package:
First find out your outdated packages:
npm outdated
Then update the package or packages that you want manually as:
npm update --save package_name
This way it is not necessary to update your local package.json
file.
Note that this will update your package to the latest ...
Type List vs type ArrayList in Java [duplicate]
...you might decide a LinkedList is the best choice for your application, but then later decide ArrayList might be a better choice for performance reason.
Use:
List list = new ArrayList(100); // will be better also to set the initial capacity of a collection
Instead of:
ArrayList list = new Array...
Why are Standard iterator ranges [begin, end) instead of [begin, end]?
...re given a range of N elements (say to enumerate the members of an array), then 0 is the natural "beginning" so that you can write the range as [0, N), without any awkward offsets or corrections.
In a nutshell: the fact that we don't see the number 1 everywhere in range-based algorithms is a direct...
How can I check if a command exists in a shell script? [duplicate]
...e following should work:
if ! type "$foobar_command_name" > /dev/null; then
# install foobar here
fi
For a real installation script, you'd probably want to be sure that type doesn't return successfully in the case when there is an alias foobar. In bash you could do something like this:
if !...
How to install PyQt4 on Windows using pip?
...e you grab the correct Windows wheel file (python version, 32/64 bit), and then use pip to install it - e.g:
C:\path\where\wheel\is\> pip install PyQt4-4.11.4-cp35-none-win_amd64.whl
Should properly install if you are running an x64 build of Python 3.5.
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Do Git tags only apply to the current branch?
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But if I do git show [tagname] then it shows a branch name above Author and Date, which contradicts "running git show <tag> to see a tag's details contains no reference to any branches"
– Brad Thomas
Jun 19 '19 ...