function-calls

问题 Please consider an Recursive function : 1) int calc(int num) { 2) sum=sum+num;//sum is a global variable 3) num--; 4) if(num==0) 5) return sum; 6) calc(num); } It calculates the sum of an integer . My teacher told me it's not recursion, but a simple function call, because you need to pass num-- as an argument and return calc(num--) . I was shocked, as I knew only one thing when a function call itself, its recursion. She also gave the reason, that line no. 2 and 3 is stored extra in stack

问题 I am calling a C dll from my VB6 application. The dll has a function call signature as follows. void WINAPI geterrstr(char* foo); where foo is a string that has to be returned. In my VB6 application, I have tried calling my dll by using the following syntax, but it returns an empty string. Declare Sub geterrstr Lib "technopnp.dll" (ByRef lpbuffer As String) Any ideas? 回答1: You should be able to; Declare Sub geterrstr Lib "technopnp.dll" (ByVal lpbuffer As String) ... dim buff as string buff

问题 code_0: (calling foo without parentheses) function foo(){ console.log('hello world'); } setTimeout(foo, 2000); This is how code_0 was executed: start -> wait for 2 seconds -> 'hello world' displayed -> end code_1: (calling foo with parentheses) function foo(){ console.log('hello world'); } setTimeout(foo(), 2000); And this is how code_1 was executed: start -> 'hello world' displayed immediately -> wait for 2 seconds -> end Why would the program perform so differently when I called the

问题 code_0: (calling foo without parentheses) function foo(){ console.log('hello world'); } setTimeout(foo, 2000); This is how code_0 was executed: start -> wait for 2 seconds -> 'hello world' displayed -> end code_1: (calling foo with parentheses) function foo(){ console.log('hello world'); } setTimeout(foo(), 2000); And this is how code_1 was executed: start -> 'hello world' displayed immediately -> wait for 2 seconds -> end Why would the program perform so differently when I called the

问题 How to pass Editor1 as Parameter: In my aspx.cs i am giving a call to a function which is in .cs file for the same project, as follows: protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e) { DropDown abs = new DropDown(); abs.dd(this.DropDownList2, this.DropDownList3); } .CS file code public void dd(DropDownList DropDownList2, DropDownList DropDownList3) { //My code which contains DropDownList2 DropDownList3 and Editor1 } The error that i am getting is: Error 1 The

问题 First question on stackoverflow :) I'm relatively new to C++, and have never used templates, so forgive me if I'm doing something silly. I have a template function that combs through a list and checks for a specified element of a general type. That way I can specify whether it's looking for a string, or an int, or whatever. template <class T> bool inList(T match, std::string list) { int listlen = sizeof(list); for (int i = 0; i <= listlen; i++) { if (list[i] == match) return true; else

问题 What's the most elegant way of performing a delayed (and therefore also asynchronous) functional call using C++11, lambdas and async? Suggested naming: delayed_async . Reason for asking is that I want a GUI alert light to be switched off after given time (in this case one second) without blocking the main (wxWidgets main loop) thread of course. I've use wxWidgets' wxTimer for this and I find wxTimer rather cumbersome to use in this case. So that got my curious about how much more convenient

问题 This question already has answers here : Order of function calling (5 answers) Closed 6 years ago . Is there some definite order in which the functions are called in the expression below or does it vary from compiler to compiler? Does the following rule apply here - In C, the order in which arguments to functions and operands to most operators are evaluated is unspecified. Found the above rule in this wiki page a = (f1(10, 20) * f2(30, 40)) + f3() 回答1: The rule does apply. f1 , f2 , and f3

问题 This is in fact an interview question, I can't figure out the answer. Anyone knows about this? You can talk about any difference, for example, the data that are push into stack. 回答1: Though virtualism/dynamic dispatch is strictly implementation defined, most(read all known ) compilers implement it by using vptr and vtable . Having said that, the difference between calling a non virtual function and virtual function is: Non-virtual functions are resolved statically at Compile-time , While

问题 What is the difference between the following? onClick="javascript: function('value');" onClick="function('value');" When do I use the javascript: before the function call, and why? Can I call the function without using javascript: prefix? Please help me understand the difference. 回答1: In an element's inline event handler, like onclick , onchange , onsubmit , etc., you do not need the javascript: prefix - the reason you often see it is because people confuse it with the href syntax that I