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How to get the first line of a file in a bash script?
... a bash variable the first line of a file. I guess it is with the grep command, but it is any way to restrict the number of lines?
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Best practices for Storyboard login screen, handling clearing of data upon logout
...controller is a Tab Bar Controller. I'm creating the login/logout process, and it's mostly working fine, but I've got a few issues. I need to know the BEST way to set all this up.
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How to replace NaN values by Zeroes in a column of a Pandas Dataframe?
I have a Pandas Dataframe as below:
12 Answers
12
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C++ equivalent of Java's toString?
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In C++ you can overload operator<< for ostream and your custom class:
class A {
public:
int i;
};
std::ostream& operator<<(std::ostream &strm, const A &a) {
return strm << "A(" << a.i << ")";
}
This way you can output instances ...
What does Maven Update Project do in Eclipse?
...ava version, you will find that Eclipse will ask you to update the project and afterwards the configured Java runtime in the project will have changed to reflect what your Maven pom indicates.
That is an important thing to keep in mind: the Maven pom is the lead in this kind of project setup. If yo...
Two single-column indexes vs one two-column index in MySQL?
I'm faced with the following and I'm not sure what's best practice.
4 Answers
4
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How to preview git-pull without doing fetch?
...EAD..origin/master to show the log entries between your last common commit and the origin's master branch. To show the diffs, use either git log -p HEAD..origin/master to show each patch, or git diff HEAD...origin/master (three dots not two) to show a single diff.
There normally isn't any need to u...
Javascript - removing undefined fields from an object [duplicate]
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A one-liner using ES6 arrow function and ternary operator:
Object.keys(obj).forEach(key => obj[key] === undefined ? delete obj[key] : {});
Or use short-circuit evaluation instead of ternary: (@Matt Langlois, thanks for the info!)
Object.keys(obj).forEach(...
How can I strip all punctuation from a string in JavaScript using regex?
...ly a quantifier to the preceding, so in this case it's replacing between 2 and 100 whitespace characters (\s) with a single space. If you want to collapse any number of whitespace characters down to one, you would leave off the upper limit like so: replace(/\s{2,}/g, ' ').
– Mi...
How do 20 questions AI algorithms work?
...nstead of taking into account all questions which have been answered, you randomly pick a smaller subset, which is enough to give you a single answer. Now you repeat that a few times with different random subset of questions, till you see that most of the time, you are getting the same result. you t...