for-loop

问题 I'm trying to push to a two-dimensional array without it messing up, currently My array is: var myArray = [ [1,1,1,1,1], [1,1,1,1,1], [1,1,1,1,1] ] And my code I'm trying is: var r = 3; //start from rows 3 var c = 5; //start from col 5 var rows = 8; var cols = 7; for (var i = r; i < rows; i++) { for (var j = c; j < cols; j++) { myArray[i][j].push(0); } } That should result in the following: var myArray = [ [1,1,1,1,1,0,0], [1,1,1,1,1,0,0], [1,1,1,1,1,0,0], [0,0,0,0,0,0,0], [0,0,0,0,0,0,0], [0

问题 This question already has answers here : python: restarting a loop (5 answers) Closed 3 years ago . Basically, I need a way to return control to the beginning of a for loop and actually restart the entire iteration process after taking an action if a certain condition is met. What I'm trying to do is this: for index, item in enumerate(list2): if item == '||' and list2[index-1] == '||': del list2[index] *<some action that resarts the whole process>* That way, if ['berry','||','||','||',

问题 Which one is better, using all the *fun functions ( arrayfun , cellfun , structfun and spfun ) or simply using for loop? What method gives better performance and which methods should be considered better practice in terms of readability of the code? 回答1: It really depends on what you call 'performance' :) If you mean minimum execution time , well, sometimes *fun are faster (for example, cellfun('isempty', ...); (yes, string argument!) for sure beats the loop version). Sometimes a loop is

问题 I want to convert simple loops in high-level languages into assembly language (for emu8086) say, I have this code: for(int x = 0; x<=3; x++) { //Do something! } or int x=1; do{ //Do something! } while(x==1) or while(x==1){ //Do something } How do I do this in emu8086? 回答1: For-loops: For-loop in C: for(int x = 0; x<=3; x++) { //Do something! } The same loop in 8086 assembler: xor cx,cx ; cx-register is the counter, set to 0 loop1 nop ; Whatever you wanna do goes here, should not change cx inc

问题 This is a rather silly question but why is int commonly used instead of unsigned int when defining a for loop for an array in C or C++? for(int i;i<arraySize;i++){} for(unsigned int i;i<arraySize;i++){} I recognize the benefits of using int when doing something other than array indexing and the benefits of an iterator when using C++ containers. Is it just because it does not matter when looping through an array? Or should I avoid it all together and use a different type such as size_t ? 回答1:

问题 I want to run a sh file: #!/bin/bash for f in !(*.sh); do ffmpeg -i "$f" -vf yadif=0:-1 -threads 0 -c:v libx264 -pix_fmt yuv420p \ -r 29.97 -b:v 3000k -s 1280x720 -preset:v slow -profile:v Main \ -level 3.1 -bf 2 -movflags faststart /mnt/media/out-mp4/"${f%.mxf}.mp4" rm $f done However, I get the following error: 2: task1.sh: Syntax error: "(" unexpected If I try directly on the command line it works perfectly. the path and permissions are already reviewed Any idea what might be happening?

问题 Hi so basically my question is what does a for loop without any curly braces around it do? So from what I know, that during an if-statement only the first line of the code is executed. So in a for loop how does it work? I don't really understand the concept of a loop without the braces and with the braces. I guess an explanation with a piece of code would help. This is in C by the way. Here's a code I've been looking at as a reference. int main(int argc, char* argv[]) { int i; int count = 0;

问题 How can I loop through a List and grab each item? I want the output to look like this: Console.WriteLine("amount is {0}, and type is {1}", myMoney.amount, myMoney.type); Here is my code: static void Main(string[] args) { List<Money> myMoney = new List<Money> { new Money{amount = 10, type = "US"}, new Money{amount = 20, type = "US"} }; } class Money { public int amount { get; set; } public string type { get; set; } } 回答1: foreach : foreach (var money in myMoney) { Console.WriteLine("Amount is

问题 In the object below, I'd like to change the property name, thumb , to thumbnail . I'd also like to change the values of the title to include <span> tags. Here's my object: var data = [{ thumb: '/images/01.png', title: 'My title', },{ thumb: '/images/02.png', title: 'My title', },{ thumb: '/images/03.png', title: 'My title', }]; here's how I'd like it to look: var data = [{ thumbnail: '/images/01.png', title: '<span class="red">title 1</span>', },{ thumbnail: '/images/02.png', title: '<span

问题 All over the web, code samples have for loops which look like this: for(int i = 0; i < 5; i++) while I used the following format: for(int i = 0; i != 5; ++i) I do this because I believe it to be more efficient, but does this really matter in most cases? 回答1: Everybody loves their micro-optimizations, but this would not make a difference as far as I can see. I compiled the two variations with g++ on for Intel processors without any fancy optimizations and the results are for for(int i = 0; i <