while-loop

问题 What I am trying to do is to create a while loop where a program menu is run from until the user inputs a valid response. However the scanner instance I have created does not want to play ball and keeps throwing NoSuchElementExceptions no matter what I have tried. import java.util.Scanner; public class Menu { Menu() { isValid = false; uInput = 0; } public int mMain() { Scanner in2; do { in2 = new Scanner(System.in); //For user input System.out.println("Please choose from the following options

问题 Just trying to write a program that will take the users input and add it to the list 'numbers': print "Going to test my knowledge here" print "Enter a number between 1 and 20:" i = raw_input('>> ') numbers = [] while 1 <= i <= 20 : print "Ok adding %d to numbers set: " % i numbers.append(i) print "Okay the numbers set is now: " , numbers However when I execute the program it only runs to raw_input() Going to test my knowledge here Enter a number between 1 and 20: >>> 4 Is there some

问题 In C# a question has been bugging me for a while and its what is that actual major difference between a While and For Loop. Is it just purely readability ie; everything you can essentially do in a for loop can be done in a while loop , just in different places. So take these examples: int num = 3; while (num < 10) { Console.WriteLine(num); num++; } vs for (int x = 3; x < 10; x++) { Console.WriteLine(x); } Both code loops produce the same outcome and is the only difference between the two that

问题 I have this C++ program with the following general structure 1st while (condition A == true) //some code for 1st loop 2nd while (condition B == true) //some code for 2nd loop try //some code for try catch //condition B == false (supposed to leave 2nd loop and go back to first loop) I want it to get out of 2nd loop when there's an exception and go back to 1st loop until condition B is tue again. As described above it doesn't work as I expect. What seems to be happening is that code gets stuck

问题 There is any way to do it like C/C# ? For example (C# style) for( int i=0; i<100; i++) { if(i==66) break; } 回答1: The short answer is no. You would generally use some higher-order function to express the same functionality. There is a number of functions that let you do this, corresponding to different patterns (so if you describe what exactly you need, someone might give you a better answer). For example, tryFind function returns the first value from a sequence for which a given predicate

问题 I was trying to figure out what statement to use to get the user to enter a number between 1 and 10. here is what i have so far. int a; printf("Enter a number between 1 and 10: \n); scanf("%d", &a); 回答1: int input; while (true){ scanf("%d",&input); if (input>=1 && input<=10){ // process with your input then use break to end the while loop } else{ printf("Wrong input! try Again."); continue; } } 回答2: Number beteween 1 to 10 right? so first stage you must validate if input is integer or not

问题 How to go back to menu using case in switch case without using GOTO command. So this is the sample: while(1){ printf("1: Basic Math\n2. Intermediate Math\n3. Advance Math"); printf("Enter your choice: "); int choice; scanf("%d", &choice); switch(choice) int theChoices; case 1: printf("1. Add\n 2. Subtract\n3. Go back to menu"); scanf("%d", &theChoices); switch (theChoices) { case 1: //calculation ... case 2: //calculation ... case 3: // Go Back to menu which is Basic math, Intermediate Math,

问题 Im trying to get this loop to work, but it just refuses to work. Any help would be very much appreciated. while player1_score < 100 and player2_score < 100 and player3_score < 100 and player4_score < 100: while player_turn != playerholder: dice_rolling() scoring() score_awarding() player_turn = player_turn + 1 if player_turn == playerholder: player_turn == 1 What im trying to do is get the number of players present (playerholder) and then keep player turn within the bounds of it i.e repeating

问题 This question already has an answer here : Issues getting table headers to position correctly (1 answer) Closed 4 years ago . I am designing a table and I am having difficulties with a <th> . The <th> is usernames from my database, so I need to fetch them, so that they can even display on the page. I am currently fetching everything from my database table through a fetch while loop. Whenever, I put the <th> in my loop it ruins the structure of my table. I am trying to create a table that

问题 I have translated this code to VB.NET which is a function to check if a image is grayscale. private static unsafe bool IsGrayScale(Image image) { using (var bmp = new Bitmap(image.Width, image.Height, PixelFormat.Format32bppArgb)) { using (var g = Graphics.FromImage(bmp)) { g.DrawImage(image, 0, 0); } var data = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, bmp.PixelFormat); var pt = (int*)data.Scan0; var res = true; for (var i = 0; i < data.Height * data