function

问题 This is a follow up to my earlier question. I wanted to compare the results I get back from filling out a form. This is what I have so far: const eqObj = (obj, source) => Object.keys(source).every(key => obj.hasOwnProperty(key) && obj[key] === source[key]); $('#btn').on('click', function() { let $inputs = $('#new_form :input'); let new_vals = {}; $inputs.each(function() { new_form[this.id] = $(this).val(); }); console.log(new_vals); $.getJSON(api, function(data) { data.forEach(d => { console

问题 Here is a C++ code I wrote to default to user input when arguments are not provided explicitly. I have been learning Python-3.7 for the past week and am trying to achieve a similar functionality. This is the code I tried: def foo(number = int(input())): print(number) foo(2) #defaults to user input but prints the passed parameter and ignores the input foo() #defaults to user input and prints user input This code works, but not quite as intended. You see, when I pass an argument to foo() , it

问题 I have been searching this and have found this link to be helpful with renaming passed columns from a function (the [,column_name] code actually made my_function1 work after I had been searching for a while. Is there a way to use the pipe operator to rename columns in a dataframe within a function? My attempt is shown in my_function2 but it gives me an Error: All arguments to rename must be named or Error: Unknown variables: col2 . I am guessing because I have not specified what col2 belongs

问题 I have been searching this and have found this link to be helpful with renaming passed columns from a function (the [,column_name] code actually made my_function1 work after I had been searching for a while. Is there a way to use the pipe operator to rename columns in a dataframe within a function? My attempt is shown in my_function2 but it gives me an Error: All arguments to rename must be named or Error: Unknown variables: col2 . I am guessing because I have not specified what col2 belongs

问题 here is the fatal error: Fatal error: Constant expression contains invalid operations I get a fatal error in this code: <?php class InfoClass { private $user_agent = $_SERVER['HTTP_USER_AGENT']; // error is on this line public static function getOS() { global $user_agent; $os_platform = "Unknown OS Platform"; ... } i am using php 7. why is this error showing? thanks 回答1: Do This Instead <?php class InfoClass { private $user_agent; public function __construct(){ $this->user_agent = $_SERVER[

问题 How can I implement "positional-only parameter" for a function that is user defined in python? def fun(a, b, /): print(a**b) fun(5,2) # 25 fun(a=5, b=2) # should show error 回答1: The only solution would be to use a * -parameter, like so: def fun(*args): print(args[0] ** args[1]) But this comes with its own problems: you can't guaranteed the caller will provide exactly two arguments; your function has to be prepared to handle 0 or 1 arguments. (It's easy enough to ignore extra arguments, so I

问题 How can I implement "positional-only parameter" for a function that is user defined in python? def fun(a, b, /): print(a**b) fun(5,2) # 25 fun(a=5, b=2) # should show error 回答1: The only solution would be to use a * -parameter, like so: def fun(*args): print(args[0] ** args[1]) But this comes with its own problems: you can't guaranteed the caller will provide exactly two arguments; your function has to be prepared to handle 0 or 1 arguments. (It's easy enough to ignore extra arguments, so I

问题 When creating a function in R, we usually specify the number of argument like function(x,y){ } That means it takes only two arguments. But when the numbers of arguments are not specified (For one case I have to use two arguments but another case I have to use three or more arguments) how can we handle this issue? I am pretty new to programming so example will be greatly appreciated. 回答1: d <- function(...){ x <- list(...) # THIS WILL BE A LIST STORING EVERYTHING: sum(...) # Example of inbuilt

问题 I have 2 different sized structs and I would like to have one function in which I can pass them into. However, I do not know how to define the parameter of the function to accept 2 different structs. My structs are below struct { int a; // 2 byte int b; // 2 byte int c; // 2 byte int d; // 2 byte } person1; // 8 bytes struct { int a; // 2 byte DeviceAddress b; // 8 bytes int c // 2 bytes float d; // 4 bytes } person2; // 16 bytes function print_struct(struct& ?????) { actions here.... } print

问题 I want a std::vector to contain some functions, and that more functions can be added to it in realtime. All the functions will have a prototype like this: void name(SDL_Event *event); I know how to make an array of functions, but how do I make a std::vector of functions? I've tried this: std::vector<( *)( SDL_Event *)> functions; std::vector<( *f)( SDL_Event *)> functions; std::vector<void> functions; std::vector<void*> functions; But none of them worked. Please help 回答1: Try using a typedef: