anonymous-function

问题 I've got this kind of script I need to inject into ! function(e) { function doSomething() { } } Basically I get a reference to doSomething, when my code is called via Function object, but I need to hook to doSomething, so I need an original reference to id. Since doSomething is declared inside anonymous function I can't get to it. Question is, can I somehow inject code into the scope of anonymous function, Greesemonkey or any other tool. 回答1: Javascript doesn't make it easy to get values from

问题 I've defined a list of anonymous functions which use a variable defined in an outer scope. funclist <- list() for(i in 1:5) { funclist[[i]] <- function(x) print(i) } funclist[[1]]('foo') The output is: [1] 5 It seems that i is captured by reference. I'd like it to be captured by value, i.e. the output should be [1] 1 Is there a way to tell R to capture i by value rather than by reference? 回答1: When you run a for loop, this creates a variable in the environment the loop is run in, and

问题 I am accessing a property of an object returned from a resolved promise. return new Promise((resolve) => { // Get result resolve(result) }).then(r => console.log(r.id)) Typescript compiles the code and the code works but my IDE is complaining about r.id [ts] Property 'id' does not exist on type '{}'. What is the 'TypeScript' method of dealing with this? This question seems to have the same issue but I cannot understand the given solutions. This answer talks about using interfaces but im not

问题 There is the following anonymous recursive function: $f = function($n) use (&$f) { return ($n == 1) ? 1 : $n * $f($n - 1); }; echo $f(5); // 120 I try to rewrite to version 7.4, but there is an error, please tell me what I'm missing? $f = fn($n) => ($n == 1) ? 1 : $n * $f($n - 1); echo $f(5); Notice: Undefined variable: f Fatal error: Uncaught Error: Function name must be a string 回答1: Just like Barmar said, you can't use $f from the outside scope, because when the implicit binding takes

问题 What is the difference between ResultType result = await Task.Run(() => GetResultAsync()) and ResultType result = await Task.Run(async() => await GetResultAsync()) I would speculate that the former would fire and forget GetResultAsync() , since it is not awaited, but then how does it get the result? I am surprised that the return type of the former Task.Run is Task<ResultType> and not Task<Task<ResultType>> . 回答1: Both do the same from perspective of result. In both cases the overload Task

问题 What is the difference between ResultType result = await Task.Run(() => GetResultAsync()) and ResultType result = await Task.Run(async() => await GetResultAsync()) I would speculate that the former would fire and forget GetResultAsync() , since it is not awaited, but then how does it get the result? I am surprised that the return type of the former Task.Run is Task<ResultType> and not Task<Task<ResultType>> . 回答1: Both do the same from perspective of result. In both cases the overload Task

问题 What is the difference between ResultType result = await Task.Run(() => GetResultAsync()) and ResultType result = await Task.Run(async() => await GetResultAsync()) I would speculate that the former would fire and forget GetResultAsync() , since it is not awaited, but then how does it get the result? I am surprised that the return type of the former Task.Run is Task<ResultType> and not Task<Task<ResultType>> . 回答1: Both do the same from perspective of result. In both cases the overload Task

问题 Merged with var functionName = function() {} vs function functionName() {}. I am wondering if anyone knows why some people define global variables that are set to functions vs just defining a global function name. For example: var foo = function() { alert('hello!'); } instead of function foo() { alert('hello!'); } Wouldn't the second method be better since there is a chance something might overwrite the first variable and you would lose the function? Does this have anything to do with

问题 Merged with var functionName = function() {} vs function functionName() {}. I am wondering if anyone knows why some people define global variables that are set to functions vs just defining a global function name. For example: var foo = function() { alert('hello!'); } instead of function foo() { alert('hello!'); } Wouldn't the second method be better since there is a chance something might overwrite the first variable and you would lose the function? Does this have anything to do with

问题 While making several test projects for my small library of code I have come across many tutorials that go about making functions in many different ways. For example: Function Declarations FunctionDeclaration : function Identifier ( FormalParameterList opt ){ FunctionBody } Function Expressions FunctionExpression : function Identifier opt ( FormalParameterList opt ){ FunctionBody } Anonymous Self-Executing Functions (function(msg){ alert(msg); })('SO'); // alerts "SO" Anonymous Self-Executing