infinite-loop

问题 I believe this is a very simple question, but I can't find a simple answer to it. I have an infinite loop, e.g. while(1) , for(;;) , and I need to break from the loop on a keypress. What is the easiest way to do this? P.S.: I can't use getch , cin.ignore , or cin.get because it stops the loop. 回答1: Well, what you want is asynchronous input. All of the methods provided by cin wait for enter. You will have to use system-specific functions for that, or use a library that will do it for you. What

问题 My program has an endless loop, when I use try and catch block in a while loop . import java.util.*; class Try { public static void main(String args[]) { Scanner sc=new Scanner(System.in); while(true) { try { System.out.println("Enter a no "); int s=sc.nextInt(); } catch(Exception e) { System.out.println("Invalid input try again"); } } } } When I input an integer, it runs fine and asks for another input, but when I input a char, it goes for endless loop. Why is this so? 回答1: Your program

问题 My program has an endless loop, when I use try and catch block in a while loop . import java.util.*; class Try { public static void main(String args[]) { Scanner sc=new Scanner(System.in); while(true) { try { System.out.println("Enter a no "); int s=sc.nextInt(); } catch(Exception e) { System.out.println("Invalid input try again"); } } } } When I input an integer, it runs fine and asks for another input, but when I input a char, it goes for endless loop. Why is this so? 回答1: Your program

问题 This question already has answers here : try/catch with InputMismatchException creates infinite loop (7 answers) Closed 4 years ago . I keep getting my code caught in an infinite while loop. It is nothing to advanced, but i can not figure it out for the life of me! Someone Please help I have purplosely just re created the specific error without all of the if statements i have in my actual program. package bs; import java.util.InputMismatchException; import java.util.Scanner; public class bs {

问题 This question already has answers here : Semicolon at end of 'if' statement (18 answers) Closed 2 years ago . boolean r = false ; int s = 0 ; while (r == false) ; { s = getInt() ; if (!(s>=0 && s<=2)) System.out.println ("try again not a valid response") ; else r = true ; } The text never displays itself even when a 3 or a 123 is entered and the loop never terminates. Whats wrong here? 回答1: You have a semicolon after the condition. When you use braces to specify a block for your while you don

问题 This is a tangent from the question here: Returning value to Javascript from PHP called from XMLHttpRequest I am adding an "image upload" button to my AjaxChat. I am using an XMLHttpRequest to send the image to the server, where I run a PHP script to move it to my images folder. Below is the Javascript function in charge of opening the XMLHttpRequest connection and sending the file: function uploadImage() { var form = document.getElementById('fileSelectForm'); var photo = document

问题 My programm is freezing when I write getters/setters for OneToMany properties. I have these two entities : COMPETENCE_LEVEL @Entity @Table(name="competence_level") public class CompetenceLevel { @Id @GeneratedValue(strategy=GenerationType.AUTO) @Column(name="id_competence_level") private Long idCompetenceLevel; @ManyToOne @JoinColumn(name="id_competence") private Competence competence; @ManyToOne @JoinColumn(name="id_level") private Level level; @ManyToOne @JoinColumn(name="id_profil")

问题 For example I have something like this : <?php header("Content-Type: text/html; charset=UTF-8"); set_time_limit(0); ob_start("ob_gzhandler"); while(true) : echo microtime(true)."<br>"; ob_flush(); flush(); sleep(1); endwhile; ob_end_clean(); ?> This code works on my localhost and each second on the page is printed microtime() , but when I try to run same script on my Shared Linux Hosting nothing is printed, page just has infinite loading time. How to print something when in infinite loop, on

问题 I have the latest Chrome, I'm building an extension. Consider the following code: var returnTab = false; // init the variable as false var createNewTab = function(){ returnTab = false; // make sure we start with this var as false chrome.tabs.create({url:'http://www.google.com/'}, function(tab){ returnTab = tab; // put the returntab object inside the variable }); while(returntab===false){ }; // wait for the tab to be created. return returnTab; }; c = createNewTab(); All fine and it should work

问题 I have a little project I'm working on, it's fairly simple so I'm hoping someone can help me. I'm using a raspberry pi to dim a single LED with some very crude PWM. my PWM code looks like this: import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BCM) GPIO.setup(7, GPIO.OUT) frequency = 0.005 dwell = 0.0001 while True: time.sleep(frequency) GPIO.output(7, 1) time.sleep(dwell) GPIO.output(7, 0) Basically, in order for the LED to remain lit at the brightness determined by "dwell" I need that