Java:在使用其他方法后如何回到主方法
我对Java相当陌生,我遇到的问题是,这段代码可以编译,但在十六进制转换后不会运行;而是在hexartodecimal方法之后结束。我不能重用main方法,也不知道如何调用intreverse方法并实际运行它。有没有办法回到main或者我需要打电话到什么地方
import java.util.Scanner;
public class Homework4 {
public static void main(String[]args) {
// Sum and average of a set of intergers entered by the user
// First we will declare some variables
int userInput = 1;
int positives = 0;
int negatives = 0;
int sum = 0;
int numCount = 0;
Scanner input = new Scanner(System.in);
// Will start a while loop that will stop when user enters 20 integers
while ((numCount <= 20)) {
System.out.println("Please enter a nonzero integer or enter 0 to finish ");
userInput = input.nextInt();
if (userInput == 0) {
break;
} else if (userInput > 0) {
positives += 1;
numCount += 1;
sum = sum + userInput;
} else if (userInput < 0) {
negatives += 1;
numCount += 1;
sum = sum + userInput;
} else
System.out.println("Error, please enter an integer");
continue;
}
double average = (sum / numCount);
System.out.println("The sum of the entered integers is " + sum);
System.out.println("The average of the enetered integers is " + average);
System.out.println("There are " + positives + " positive integers and " + negatives + " negative integers");
// Convert Hexadecimal number to decimal
// Ask the user to input a string of 5 digits or less in hex
System.out.println("Please enter a hexadecimal number of up to 5 characters");
String hex = input.next();
if (hex.length() <= 5) {
System.out.println(hex + " in decimal value is equal to " + hexToDecimal(hex.toUpperCase()));
} else {
System.out.println("Error: please enter a hex number of 5 digits or less");
}
}
// Now we will create the method to convert to decimal
public static int hexToDecimal(String hex) {
int decimal = 0;
for (int i = 0; i < hex.length(); i++) {
char hexcharacter = hex.charAt(i);
decimal = decimal * 16 + hexCharToDecimal(hexcharacter);
}
return decimal;
}
public static int hexCharToDecimal(char ch) {
if (ch >= 'A' && ch <= 'F') // check to see if there is any letters in the string
return 10 + ch - 'A';
else
return ch - '0';
}
// Print entered integer in reverse
public static void intreverse(String[]args) {
// Ask user for an integer to be reversed
Scanner input = new Scanner(System.in);
System.out.println("Please enter an integer to be reversed");
int number = input.nextInt();
reverse(number); // Method to be called
}
// Will now state our method
public static void reverse(int number) {
// use a while loop to get each digit
while (number > 0) {
System.out.print(number % 10);
number = number / 10;
}
}
}
# 1 楼答案
将始终运行一次,因为它不包含在任何类型的循环中。如果希望在调用第二个case时再次运行,则将其包含在
while(true)
循环中,并在第一个case中使用break语句停止执行