2013-11-26 43 views
-5

这是我第二次问这个问题,因为这个任务是明天到期的,而且我还不清楚如何在我的代码中取得进展!我在AP计算机编程课,所以我是一个完整的初学者。我的目标(到目前为止)是将两个分数相乘。有什么方法可以在另一种方法中在该方法之外的特定方法内使用变量?我希望不会让人困惑,谢谢!Java分数计算器,全局变量?

import java.util.Scanner; 
import java.util.StringTokenizer; 

public class javatest3 { 
    static int num1 = 0; 
    static int num2 = 0; 
    static int denom1 = 0; 
    static int denom2 = 0; 
    public static void main(String[] args){ 
    System.out.println("Enter an expression (or \"quit\"): "); //prompts user for input 
    intro(); 

} 
public static void intro(){ 
    Scanner input = new Scanner(System.in); 
    String user= input.nextLine(); 
    while (!user.equals("quit") & input.hasNextLine()){ //processes code when user  input does not equal quit 
    StringTokenizer chunks = new StringTokenizer(user, " "); //parses by white space 
    String fraction1 = chunks.nextToken(); //first fraction 
    String operand = chunks.nextToken(); //operator 
    String fraction2 = chunks.nextToken(); //second fraction 
    System.out.println("Fraction 1: " + fraction1); 
    System.out.println("Operation: " + operand); 
    System.out.println("Fraction 2: " + fraction2); 
    System.out.println("Enter an expression (or \"quit\"): "); //prompts user for more input 


while (user.contains("*")){ 
    parse(fraction1); 
    parse(fraction2); 
    System.out.println("hi"); 
    int num = num1 * num2; 
    int denom = denom1 * denom2; 
    System.out.println(num + "/" + denom); 
    user = input.next(); 

     } 
    } 
} 

public static void parse(String fraction) { 
    if (fraction.contains("_")){ 
     StringTokenizer mixed = new StringTokenizer(fraction, "_"); 
     int wholeNumber = Integer.parseInt(mixed.nextToken()); 
     System.out.println(wholeNumber); 
     String frac = mixed.nextToken(); 
     System.out.println(frac); 
     StringTokenizer parseFraction = new StringTokenizer(frac, "/"); //parses by forward slash 
     int num = Integer.parseInt(parseFraction.nextToken()); 
     System.out.println(num); 
     int denom = Integer.parseInt(parseFraction.nextToken()); 
     System.out.println(denom); 




} 
else if (!fraction.contains("_") && fraction.contains("/")){ 
    StringTokenizer parseFraction = new StringTokenizer(fraction, "/"); //parses by forward slash 
    int num = Integer.parseInt(parseFraction.nextToken()); 
    System.out.println(num); 
    int denom = Integer.parseInt(parseFraction.nextToken()); 
    System.out.println(denom); 



}else{ 
    StringTokenizer whiteSpace = new StringTokenizer(fraction, " "); 
    int num = Integer.parseInt(whiteSpace.nextToken()); 
    System.out.println(num); 
} 
}} 
+0

你问的是错误的问题。你对特定问题的回答是否有任何方法可以在另一种方法中在该方法之外的特定方法中使用变量?总是不会。该变量被封装为局部变量。 –

+0

您可以将变量声明为全局变量。或者你可以传递变量作为参数。 – Adarsh

+1

如果这是你在这里问的同一个问题:http://stackoverflow.com/questions/20207131/java-fraction-calculator然后你应该删除这个问题 –

回答

4

有没有办法在另一种方法来使用一个变量的特定方法内部的方法之外?

是的,你可以做到这一点。你可以在一个方法中声明一个变量,在那里使用它并将它传递给另一个方法,你可能想使用它。像这样的东西

void test1() { 
    int var = 1; 
    System.out.println(var); // using it 
    test2(var); // calling other method and passing the value of var 
} 

void test2(int passedVarValue) { 
    System.out.println(passedVarValue); // using the passed value of the variable 
    // other stuffs 
}