function

问题 I'm trying to figure out what's behind va_start(), va_arg() macroses. The code below works well. #include <iostream> #include <cstdarg> void f(double a, double b, ...) { va_list arg; va_start(arg, b); double d; while((d = va_arg(arg, double)) != 0) { std::cout << d << '\n'; } } int main(int argc, char *argv[]) { f(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 0.0); return 0; } As I was expected it gave such output: 3 4 5 6 7 8 9. Then I found definitions of that macroses (in internet, cause my

问题 I have been having an interesting time building a little web scraper and I think I am doing something wrong with my variable or function scope. Whenever I try to pull out some of the functionality into separate functions it gives me the NameError: global name 'NAME' is not defined. I see that a lot of people are having a similar problem but there seems to be a lot of variation with the same error and I can't figure it out. import urllib2, sys, urlparse, httplib, imageInfo from BeautifulSoup

问题 I'm trying to creating a script to trigger an IFTTT notification. What I got working so far is: var http = require('http') var body = JSON.stringify({ value1: "Temp Humid Sensor", value2: "Error", value3: "reading measurements" }) var sendIftttTNotification = new http.ClientRequest({ hostname: "maker.ifttt.com", port: 80, path: "/trigger/th01_sensor_error/with/key/KEY", method: "POST", headers: { "Content-Type": "application/json", "Content-Length": Buffer.byteLength(body) } })

问题 I'm trying to creating a script to trigger an IFTTT notification. What I got working so far is: var http = require('http') var body = JSON.stringify({ value1: "Temp Humid Sensor", value2: "Error", value3: "reading measurements" }) var sendIftttTNotification = new http.ClientRequest({ hostname: "maker.ifttt.com", port: 80, path: "/trigger/th01_sensor_error/with/key/KEY", method: "POST", headers: { "Content-Type": "application/json", "Content-Length": Buffer.byteLength(body) } })

问题 Here is a made up example of nested functions with functions passed as parameters and functions returned: function foo() { let x = 100 function bar(a, b) { function mul(cb) { let m = x * a cb(m) } function add(cb) { let m = x + b cb(m) } function update(m) { x = m } mul(update) add(update) console.log(x) } return bar } let bar = foo() bar(2, 3) // => 203 bar(2, 3) // => 409 bar(2, 3) // => 821 bar(2, 3) // => 1645 Without figuring out potential ways in which these functions could be optimized

问题 Below I was wondering if there might be a way to extract the columns Name and Groups from vc1 and vc2 and respectively paste them as the column names for objects AA , BB . For example, for MODEL 1 (below), my expected output of AA will be: plate_(Intercept) #: Name & Groups column from `vc1` Standard deviation 1.54 Proportion of Variance 1.00 Cumulative Proportion 1.00 sample_(Intercept) #: Name & Groups column from `vc1` Standard deviation 3.513 Proportion of Variance 1.000 Cumulative

问题 VBA newbie here. I am trying to pass an array ( it is static, but please answer for dynamic range as well ) to a function. Then assign individual array elements to unique variables and use these variables in a custom formula. I just browsed around and wrote the code but keep getting #VALUE! error. The gist of the code is below: Public Function mytest(ByRef arr1 As Range) Dim A As Double Dim B As Double A = arr1(0) B = arr1(1) mytest = A + B 'The actual formula is a bit more complicated than

问题 VBA newbie here. I am trying to pass an array ( it is static, but please answer for dynamic range as well ) to a function. Then assign individual array elements to unique variables and use these variables in a custom formula. I just browsed around and wrote the code but keep getting #VALUE! error. The gist of the code is below: Public Function mytest(ByRef arr1 As Range) Dim A As Double Dim B As Double A = arr1(0) B = arr1(1) mytest = A + B 'The actual formula is a bit more complicated than

问题 When calling a Javascript function, it seems like JS gives priority to functions without parameters first, even if I have the same function name with parameters. The strange behavior only happens in the following scenario: I have a an HTML page with embedded Javascript, like this: //Javascript in the page function testAbc(){ alert('testAbc no params'); } //Javascript in common.js function testAbc(x){ alert('testAbc with param:'+x); } function testAbcFunc(x){ testAbc(x); } Now from somewhere

问题 Is there a function that generates k random numbers within a specified range. For example I want 5 random numbers between 0 to 100, with or without replacement. 回答1: You could use std::generate_n with either rand() or a generator from the new C++11 random number generators. 回答2: There is the Boost library, which you can use to generate random numbers, for example. The following code generates 5 random numbers from [0, 100] with replacement : #include <vector> #include <boost/random/mersenne