A closure is a pairing of: A function and A reference to that function’s outer scope (lexical environment) A lexical environment is part of every execution context (stack frame) and is a map between identifiers (i.e. local variable names) and values. Every function in JavaScript maintains a reference to its outer lexical environment. This reference … Read more
Reference – What does this error mean in PHP? solved Reference – What does this error mean in PHP?
Introduction Reference errors in PHP are a type of error that occurs when a variable is used without being declared or assigned a value. This type of error can be difficult to debug, as it can be caused by a variety of issues. In this article, we will discuss what a reference error is, how … Read more
Short Answer It’s boilerplate code that protects users from accidentally invoking the script when they didn’t intend to. Here are some common problems when the guard is omitted from a script: If you import the guardless script in another script (e.g. import my_script_without_a_name_eq_main_guard), then the latter script will trigger the former to run at import … Read more
Introduction If __name__ == “__main__”: is a special statement in Python that is used to execute some code only if the file is run directly. This statement is used to check whether the current file is being imported from another module or not. If the file is being imported from another module, the code inside … Read more
Consider two libraries called Foo and Bar: using namespace foo; using namespace bar; Everything works fine, and you can call Blah() from Foo and Quux() from Bar without problems. But one day you upgrade to a new version of Foo 2.0, which now offers a function called Quux(). Now you’ve got a conflict: Both Foo … Read more
Introduction Using the “using namespace std;” statement in C++ is a controversial topic among developers. While it can be a convenient way to access the standard library, it can also lead to confusion and errors. In this article, we will discuss why using namespace std; is considered bad practice and what alternatives are available. We … Read more
Amending the most recent commit message git commit –amend will open your editor, allowing you to change the commit message of the most recent commit. Additionally, you can set the commit message directly in the command line with: git commit –amend -m “New commit message” …however, this can make multi-line commit messages or small corrections … Read more
The Stack Overflow Regular Expressions FAQ See also a lot of general hints and useful links at the regex tag details page. Online tutorials RegexOne ↪ Regular Expressions Info ↪ Quantifiers Zero-or-more: *:greedy, *?:reluctant, *+:possessive One-or-more: +:greedy, +?:reluctant, ++:possessive ?:optional (zero-or-one) Min/max ranges (all inclusive): {n,m}:between n & m, {n,}:n-or-more, {n}:exactly n Differences between greedy, … Read more
Introduction Regular expressions (regex) are a powerful tool used to match patterns in text. They are used in many programming languages and applications to search, edit, and manipulate text. This article will explain what a regex is and how to interpret a regex. It will also provide an example of a regex and explain what … Read more
One does not simply redirect using jQuery jQuery is not necessary, and window.location.replace(…) will best simulate an HTTP redirect. window.location.replace(…) is better than using window.location.href, because replace() does not keep the originating page in the session history, meaning the user won’t get stuck in a never-ending back-button fiasco. If you want to simulate someone clicking … Read more
One word answer: asynchronicity. Forewords This topic has been iterated at least a couple of thousands of times, here, in Stack Overflow. Hence, first off I’d like to point out some extremely useful resources: @Felix Kling’s answer to “How do I return the response from an asynchronous call?”. See his excellent answer explaining synchronous and … Read more
Introduction Asynchronous code is a type of programming that allows multiple tasks to be executed simultaneously. This type of code can be difficult to debug, as it can be difficult to determine why a variable is not being altered after it has been modified inside of a function. In this article, we will discuss the … Read more
git-clean – Remove untracked files from the working tree Synopsis git clean [-d] [-f] [-i] [-n] [-q] [-e <pattern>] [-x | -X] [–] <path>… Description Cleans the working tree by recursively removing files that are not under version control, starting from the current directory. Normally, only files unknown to Git are removed, but if the … Read more
Some examples of how to avoid select Use Dim‘d variables Dim rng as Range Set the variable to the required range. There are many ways to refer to a single-cell range: Set rng = Range(“A1”) Set rng = Cells(1, 1) Set rng = Range(“NamedRange”) Or a multi-cell range: Set rng = Range(“A1:B10”) Set rng = … Read more