How do I define a function with optional arguments?
Try calling it like: obj.some_function( ‘1’, 2, ‘3’, g=”foo”, h=”bar” ). After the required positional arguments, you can specify specific optional arguments by name.
function
“Parameter” vs “Argument”
A parameter is the variable which is part of the method’s signature (method declaration). An argument is an expression used when calling the method. Consider the following code: Here i and f are the parameters, and anInt and 2.0 are the arguments.
Meaning of = delete after function declaration
Deleting a function is a C++11 feature: The common idiom of “prohibiting copying” can now be expressed directly: […] The “delete” mechanism can be used for any function. For example, we can eliminate an undesired conversion like this:
Return array in a function
In this case, your array variable arr can actually also be treated as a pointer to the beginning of your array’s block in memory, by an implicit conversion. This syntax that you’re using: Is kind of just syntactic sugar. You could really replace it with this and it would still work: So in the same … Read more
Cannot read property ‘addEventListener’ of null
I think the easiest approach would be to just check that el is not null before adding an event listener:
Define a global variable in a JavaScript function
As the others have said, you can use var at global scope (outside of all functions and modules) to declare a global variable: (Note that that’s only true at global scope. If that code were in a module — <script type=”module”>…</script> — it wouldn’t be at global scope, so that wouldn’t create a global.) Alternatively: In modern environments, you can assign to … Read more
strdup() – what does it do in C?
Exactly what it sounds like, assuming you’re used to the abbreviated way in which C and UNIX assigns words, it duplicates strings 🙂 Keeping in mind it’s actually not part of the ISO C standard itself(a) (it’s a POSIX thing), it’s effectively doing the same as the following code: In other words: It tries to allocate enough memory … Read more
strdup() – what does it do in C?
Exactly what it sounds like, assuming you’re used to the abbreviated way in which C and UNIX assigns words, it duplicates strings 🙂 Keeping in mind it’s actually not part of the ISO C standard itself(a) (it’s a POSIX thing), it’s effectively doing the same as the following code: In other words: It tries to allocate enough memory … Read more
C++ — expected primary-expression before ‘ ‘
You don’t need “string” in your call to wordLengthFunction(). int wordLength = wordLengthFunction(string word); should be int wordLength = wordLengthFunction(word);
How to send an email with Python?
I recommend that you use the standard packages email and smtplib together to send email. Please look at the following example (reproduced from the Python documentation). Notice that if you follow this approach, the “simple” task is indeed simple, and the more complex tasks (like attaching binary objects or sending plain/HTML multipart messages) are accomplished very rapidly. For sending email … Read more