我需要从用户输入创建一个循环。例如，他们必须输入他们想要洗牌的次数。然后它会像用户输入状态一样多次运行卡的循环。我将应用我的整个代码。
import java.util.Scanner;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Random;
public class stringVariables {
private static boolean isValid;
public static void main (String[]args) throws NumberFormatException, IOException {
//user inputs their name in this section
Scanner user_input = new Scanner (System.in);
String first_name;
System.out.print("Enter Your First Name: ");
first_name = user_input.next ();
String last_name;
System.out.print("Enter Your Last Name: ");
last_name = user_input.next ();
String full_name;
full_name = first_name + " " + last_name;
System.out.println( full_name + " Is Now Playing");
//this is the shuffle portion as well as something to see if a number is not inputed
boolean testing = false;
String pos = "";
while(true)
{
testing = false;
Scanner sc = new Scanner(System.in);
System.out.println("How many times do you want the numbers shuffled: ");
pos = sc.next();
for(int i=0; i<pos.length();i++)
{
if(!Character.isDigit(pos.charAt(i)))
testing = true;
}
if(testing == true)
{
System.out.print("Enter only numbers.. ");
continue;
}
else
{
int key = Integer.parseInt(pos);
break;
// here is going to be the loop for shuffles
// we are now going to generate their random number and add a delay after completing their name fields
delay(2000);
System.out.println(" You will be given a hand of 3 random numbers between 7-13");
delay(2000);
System.out.println(" Then, the computer will add the random numbers and if it is equal to 31, you win.");
/* end of explanation of the game, next i will create a new screen
with the user's name and numbers */
delay(4000);
System.out.println(" ");
System.out.println(" ");
System.out.println(" ");
System.out.println(" ");
System.out.println(" ");
System.out.println(" ");
System.out.println(" ");
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System.out.println(" ");
System.out.println(" ");
System.out.println(" ");
System.out.println(" ");
System.out.println("User playing: " + full_name);
System.out.println("Your lucky numbers are...");
// random number generator
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
Random rn = new Random();
int ch=1;
while(ch==1){
// get two random numbers between 7 and 13
Random r = new Random();
int num1 =7 + (int)(Math.random()*(7));
int num2 = 7 + (int)(Math.random()*(7));
int num3 = 7 + (int)(Math.random()*(7));
System.out.println(num1 + " + " + num2 + " + " + num3+ " = " + (num1 + num2 + num3 ));
int i = 0 ;
{
System.out.println( num1 + num2 + num3 );
i++ ;
}
if(num1 + num2 + num3 == 31){
System.out.println("Congratulations !! You are the Lucky Winner !!!!");
}
else
System.out.println("Better Luck Next Time");
//the play again menu. this blocks any input besides 1 or 0
Scanner sc = new Scanner(System.in);
while (true) {
System.out.println("Want To Play Again ? ANY # = YES, ANY LETTER = NO");
String input = sc.next();
int intInputValue = 0;
try {
intInputValue = Integer.parseInt(input);
break;
} catch (NumberFormatException ne) {
System.out.println("Input is not a number, type 1 to continue, or any letter to quit");
ch=Integer.parseInt(br.readLine());
}
}}
}
//delay field
public static void delay(int millis) {
try {
Thread.sleep(millis);
} catch (InterruptedException exp) {
//delay field
}
}
}
我需要做的是从
循环用户输入 boolean testing = false;
String pos = "";
while(true)
{
testing = false;
Scanner sc = new Scanner(System.in);
System.out.println("How many times do you want the numbers shuffled: ");
pos = sc.next();
for(int i=0; i<pos.length();i++)
{
if(!Character.isDigit(pos.charAt(i)))
testing = true;
}
if(testing == true)
{
System.out.print("Enter only numbers.. ");
continue;
}
else
{
int key = Integer.parseInt(pos);
break;
让它重播这个循环
// random number generator
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
Random rn = new Random();
int ch=1;
while(ch==1){
// get two random numbers between 7 and 13
Random r = new Random();
int num1 =7 + (int)(Math.random()*(7));
int num2 = 7 + (int)(Math.random()*(7));
int num3 = 7 + (int)(Math.random()*(7));
System.out.println(num1 + " + " + num2 + " + " + num3+ " = " + (num1 + num2 + num3 ));
int i = 0 ;
{
System.out.println( num1 + num2 + num3 );
i++ ;
}
在完成名称后使其循环到所需的用户输入
答案 0 :(得分：0)
为什么不使用
while(true) {
try{
pos = sc.nextInt();
break;
} catch (InputMismatchException e) {
System.out.println("Use only numbers.");
}
}
for(int i = 0; i < pos; i++) {
//do the shuffling
}
答案 1 :(得分：0)
我在代码中做了一些改动，我觉得这就是你要找的东西。只需复制粘贴代码，它应该理想。
import java.util.InputMismatchException;
import java.util.Scanner;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Random;
public class StringVariables {
public static void main(String[] args) throws NumberFormatException, IOException {
//user inputs their name in this section
Scanner sc = new Scanner(System.in);
String first_name;
System.out.print("Enter Your First Name: ");
first_name = sc.next();
String last_name;
System.out.print("Enter Your Last Name: ");
last_name = sc.next();
String full_name;
full_name = first_name + " " + last_name;
System.out.println(full_name + " Is Now Playing");
//this is the shuffle portion as well as something to see if a number is not inputed
int ch = 1;
while (ch == 1) {
int pos = 0;
System.out.println("How many times do you want the numbers shuffled: ");
while (true) {
sc = new Scanner(System.in);
try {
pos = sc.nextInt();
break;
} catch (InputMismatchException e) {
System.out.println("Use only numbers.");
}
}
// we are now going to generate their random number and add a delay after completing their name fields
delay(2000);
System.out.println(" You will be given a hand of 3 random numbers between 7-13");
delay(2000);
System.out.println(" Then, the computer will add the random numbers and if it is equal to 31, you win.");
/* end of explanation of the game, next i will create a new screen
with the user's name and numbers */
delay(4000);
for (int i = 0; i < 100; i++) {
System.out.println(" ");
}
System.out.println("User playing: " + full_name);
System.out.println("Your lucky numbers are...");
// random number generator
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int num1 = 0, num2 = 0, num3 = 0;
boolean isWinner = false;
for (int j = 0; j < pos; j++) {
num1 = 7 + (int) (Math.random() * (7));
num2 = 7 + (int) (Math.random() * (7));
num3 = 7 + (int) (Math.random() * (7));
System.out.println(num1 + " + " + num2 + " + " + num3 + " = " + (num1 + num2 + num3));
if (num1 + num2 + num3 == 31) {
System.out.println("Congratulations !! You are the Lucky Winner !!!!");
isWinner = true;
}
}
if(!isWinner){
System.out.println("Better Luck Next Time");
}
//the play again menu. this blocks any input besides 1 or 0
while (true) {
System.out.println("Want To Play Again ? ANY # = YES, ANY LETTER = NO");
String input = sc.next();
int intInputValue = 0;
try {
intInputValue = Integer.parseInt(input);
break;
} catch (NumberFormatException ne) {
System.out.println("Input is not a number, type 1 to continue, or any letter to quit");
ch = Integer.parseInt(br.readLine());
}
}
}
}
//delay field
public static void delay(int millis) {
try {
Thread.sleep(millis);
} catch (InterruptedException exp) {
//delay field
}
}
}
答案 2 :(得分：0)
虽然目前还不完全清楚您尝试实现的目标，但我尝试修改原始帖子中的代码，使其更具可读性，并以您希望的方式运行。请在下面的代码中查看我的评论，我尝试将所有评论添加到“编辑”前面，这样您就可以轻松识别出我的评论。
//EDIT: added new import to help with validating user input
import java.util.InputMismatchException;
import java.util.Scanner;
//EDIT: removed import that is no longer needed, see code changes below
//import java.io.BufferedReader;
import java.io.IOException;
//EDIT: removed import that is no longer needed, see code changes below
//import java.io.InputStreamReader;
import java.util.Random;
//EDIT: changed class name to java standard naming convention using uppercase for first letter.
public class StringVariables {
// EDIT: this variable is not used, I removed it
// private static boolean isValid;
public static void main(String[] args) throws NumberFormatException,
IOException {
// user inputs their name in this section
Scanner user_input = new Scanner(System.in);
String first_name;
System.out.print("Enter Your First Name: ");
first_name = user_input.next();
String last_name;
System.out.print("Enter Your Last Name: ");
last_name = user_input.next();
String full_name;
full_name = first_name + " " + last_name;
System.out.println(full_name + " Is Now Playing");
// this is the shuffle portion as well as something to see if a number
// is not inputed
// EDIT: removed this variable as it is no longer used in the code that
// follows.
// boolean testing = false;
// EDIT: Removed this variable in favor of using Scanner.nextInt() in
// the code below
// String pos = "";
// EDIT: Added this variable and initialized to an invalid value so that
// we can loop until a valid value is entered.
int numShuffles = -1;
while (numShuffles < 0) {
// EDIT: This variable is not needed with the new logic
// testing = false;
// EDIT: This is not needed, you already have a Scanner object above
// called user_input
// Scanner sc = new Scanner(System.in);
System.out
.println("How many times do you want the numbers shuffled? ");
try {
// EDIT: modified the lines below to fix infinite loop, forgot
// about certain Scanner behavior so switched back to
// Integer.parseInt
String inputText = user_input.next();
numShuffles = Integer.parseInt(inputText);
} catch (NumberFormatException inputException) {
System.out.print("Please enter a valid number. ");
}
} // EDIT: added closing bracket here
// EDIT: none of the code commented out below is needed when using
// the new code above.
// for(int i=0; i<pos.length();i++)
// {
// if(!Character.isDigit(pos.charAt(i)))
// testing = true;
// }
// if(testing == true)
// {
// System.out.print("Enter only numbers.. ");
// continue;
// }
//
// else
// {
// int key = Integer.parseInt(pos);
//
//
// break;
// here is going to be the loop for shuffles
// we are now going to generate their random number and add a delay
// after completing their name fields
delay(2000);
System.out
.println(" You will be given a hand of 3 random numbers between 7-13");
delay(2000);
System.out
.println(" Then, the computer will add the random numbers and if it is equal to 31, you win.");
/*
* end of explanation of the game, next i will create a new screen with
* the user's name and numbers
*/
delay(4000);
// EDIT: rather than repeating the same code over and over just use a
// loop if you want to print 25 blank lines.
for (int i = 0; i < 25; i++)
System.out.println(" ");
// EDIT: see previous comment, removed duplicate code
// System.out.println(" ");
// System.out.println(" ");
// System.out.println(" ");
// System.out.println(" ");
// System.out.println(" ");
// System.out.println(" ");
// System.out.println(" ");
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// System.out.println(" ");
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// System.out.println(" ");
// System.out.println(" ");
// System.out.println(" ");
// System.out.println(" ");
// System.out.println(" ");
System.out.println("User playing: " + full_name);
System.out.println("Your lucky numbers are...");
// random number generator
// EDIT: This BufferedReader is not needed with changes to code below
// BufferedReader br = new BufferedReader(new
// InputStreamReader(System.in));
Random random = new Random();
// EDIT: removed the following two lines to simplify the looping logic
// int ch = 1;
// while (ch == 1) {
while (true) {
// EDIT: your comment is wrong, you're creating 3 numbers here not 2
// get two random numbers between 7 and 13
// EDIT: no need to create a new Random inside the loop, you can
// re-use a single instance.
// Random r = new Random();
// EDIT: This approach is fine, but I think using the Random class
// is easier to read so I replaced your code with code that uses
// Random
// int num1 = 7 + (int) (Math.random() * (7));
// int num2 = 7 + (int) (Math.random() * (7));
// int num3 = 7 + (int) (Math.random() * (7));
// EDIT: based on your replies it seems like you want to give the user
// several changes for each run of the game and this is what you meant
// by "shuffle". I have implemented that feature below with the for loop.
boolean isWinner = false;
for (int i = 0; i < numShuffles; i++) {
int num1 = 7 + random.nextInt(7);
int num2 = 7 + random.nextInt(7);
int num3 = 7 + random.nextInt(7);
System.out.println(num1 + " + " + num2 + " + " + num3 + " = "
+ (num1 + num2 + num3));
// EDIT: you never use the variable i so I removed this code.
// int i = 0;
// {
// System.out.println(num1 + num2 + num3);
// i++;
// }
if (num1 + num2 + num3 == 31) {
isWinner = true;
System.out
.println("Congratulations !! You are the Lucky Winner !!!!");
break;
}
}
if (!isWinner)
System.out.println("Better Luck Next Time");
// the play again menu. this blocks any input besides 1 or 0
// EDIT: again, re-use the existing scanner
// Scanner sc = new Scanner(System.in);
// EDIT: There is a much simpler and easier-to-read way to do this
// so I have removed your code and added new code after.
// EDIT: Also this code does not work correctly, it fails to exit
// properly when the user enters a letter.
// while (true) {
// System.out.println("Want To Play Again ? ANY # = YES, ANY LETTER = NO");
// String input = user_input.next();
// int intInputValue = 0;
// try {
//
// intInputValue = Integer.parseInt(input);
// Integer.parseInt(input);
// break;
// } catch (NumberFormatException ne) {
// System.out.println("Input is not a number, type 1 to continue, or any letter to quit");
//
// ch = Integer.parseInt(br.readLine());
// }
//
// }
// EDIT: here is the new code, see previous comment.
System.out
.println("Do you want to play again? (If you do enter y or yes) ");
String input = user_input.next();
if (!"y".equalsIgnoreCase(input) && !"yes".equalsIgnoreCase(input)) {
break;
}
}
// EDIT: close the scanner when you're finished with it.
user_input.close();
}
// delay field
public static void delay(int millis) {
try {
Thread.sleep(millis);
} catch (InterruptedException exp) {
// delay field
}
}
}