loops

问题 I write something like this in Ruby: if a.max == a[0] brand = b[0] elsif a.max == a[1] brand = b[1] elsif a.max == a[2] brand = b[2] elsif a.max == a[3] brand = b[3] end a and b both are unique arrays. Is there any way to check all if and elsif 's in the same condition? Only one condition for a[0] , a[1] , a[2] and a[3] ? 回答1: Array#index might help in cases like these (assuming the size of a and b is the same): brand = b[a.index(a.max)] In cases in which the array a might be empty, you will

问题 I'm trying to write a console application (C# .NET) that makes use of un-managed code in a 3rd party DLL. The external assembly makes extensive use of callbacks. The sample application I have uses Windows Forms. The sample code (Windows Forms) makes use of ThreadPool.QueueUserWorkItem ThreadPool.QueueUserWorkItem(new WaitCallback(ConnectToControlPanel)); It would seem that with windows forms there is a message pump that handles the callbacks. This is not the case with a console app so I need

问题 How would I write the following for loop using an enhanced for loop> int [] info = {1,2,3,4,5,6,7,8,9,10}; int i; for (i = 0; i < info.length; i++) { if ((i+1) % 10 == 0) System.out.println(info[i]); else System.out.println(info[i] + ", "); } I am trying the following, but i guess im doing it incorreclty for(int i: info){ body here/// 回答1: Your syntax is correct. The difference is only that you're assigning the actual int value to i instead of the loop index. Thus, if you replace (i+1) % 10

问题 How would I write the following for loop using an enhanced for loop> int [] info = {1,2,3,4,5,6,7,8,9,10}; int i; for (i = 0; i < info.length; i++) { if ((i+1) % 10 == 0) System.out.println(info[i]); else System.out.println(info[i] + ", "); } I am trying the following, but i guess im doing it incorreclty for(int i: info){ body here/// 回答1: Your syntax is correct. The difference is only that you're assigning the actual int value to i instead of the loop index. Thus, if you replace (i+1) % 10

问题 I have been trying many ways , but I am not getting to solve the problem. I found here, here and here, but I couldn’t adapt them to my problem. I would like to pass the combination of two string vectors where each element of 'pop' would be combined with each element of 'territ' and over a subset of the column “enroll” through a numeric vector (“enroll_lines”). So, there are three iterations inside the svyby function I want to do: two over a string vector and one iteration inside a subset

问题 I use these two simple loops to search through a grid from height to bottom, right to left. for(int y=0; y<height; y++){ for(int x=width; x>=0; x--){ } } Basically, I want to search through the grid sideways like the numbers in the picture below until it covers all the cells. My approach hasn't worked out well so I'm asking for help here. How can I accomplish this the quickest way possible? I believe this should be possible to do using just two loops but I can't figure it out. 回答1: The

问题 Reading the docs, I noticed a sentence saying: "Rust doesn't have a C style for loop.". So, I wonder, how can I make a loop equivalent to for(i = 0; i < 10; i += 2) { } ? The ways I can think of are something like: for i in 0..10 { if i % 2 == 0 { //Do stuff } } Or even: let i = 0; loop { if i < 10 { //Do stuff i += 2; } else { break; } } But I'm not sure this is the best way, especially since it's really verbose. Is there a better way ? I'm guessing it would be with iterators , but I'm not

问题 i've been instructed to create a function that takes values from an array and squares each value, and logging the numbers to the console. i've attempted two methods, neither of which work so far: first attempt: var numbers = [2, 7, 13, 24]; function squareAll(numbers) { var newArray = []; for(i = 0; i < numbers.length; i++) { numbers = newArray.push(Math.pow(numbers[i], 2)) return newArray; } console.log(squareAll(numbers)); } second attempt: var numbers = [2, 7, 9, 25]; var newArray = [];

问题 I am rather new to R and could use some basic help. I'd like to generate sums of two normal random variables (variance = 1 for each) as their means move apart and plot the results. The basic idea: if the means are sufficiently far apart, the distribution will be bimodal. Here's the code I'm trying: x <- seq(-3, 3, length=500) for(i in seq(0, 3, 0.25)) { y <- dnorm(x, mean=0-i, sd=1) z <- dnorm(x, mean=0+i, sd=1) plot(x,y+z, type="l", xlim=c(-3,3)) } Several questions: Are there better ways to

问题 I am rather new to R and could use some basic help. I'd like to generate sums of two normal random variables (variance = 1 for each) as their means move apart and plot the results. The basic idea: if the means are sufficiently far apart, the distribution will be bimodal. Here's the code I'm trying: x <- seq(-3, 3, length=500) for(i in seq(0, 3, 0.25)) { y <- dnorm(x, mean=0-i, sd=1) z <- dnorm(x, mean=0+i, sd=1) plot(x,y+z, type="l", xlim=c(-3,3)) } Several questions: Are there better ways to