java - 字符串数组的 parseDouble 元素

Question

我正在尝试编写一个 Java 程序来分析文本文件中字符串数组中的每个字符串，如果数字解析为 double ，则程序会打印它前面的单词和后面的单词。我似乎无法找出如何解析字符串数组的每个元素。目前它只会打印第一个数字和后面的单词，而不是前面的单词。希望有人能帮忙。

我的文本文件如下:

假设 49 个人正在切蛋糕，将其分给 5 个人。我给自己切了一大块，占 33.3%整个蛋糕。现在轮到你切一 block 蛋糕了。你也会削减 33.3% 的份额吗？或者你会把剩下的 66.6% 的蛋糕平分 4 份比较公平？你要切多大的片？

这是我的代码:

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

import javax.swing.JOptionPane;


public class NumberSearch {

public static void main(String args[]) throws FileNotFoundException {

    //creating File instance to reference text file in Java
//    String filedirect = JOptionPane.showInputDialog(null, "Enter your file"); 
    File text = new File("cakeQuestion2.txt");

    //Creating Scanner instance to read File in Java

    Scanner scnr = new Scanner(text);

    //Reading each line of file using Scanner class
    int lineNumber = 1;
    while(scnr.hasNextLine())
    {

        String line = scnr.nextLine();
        lineNumber++; 

//Finding words


           String[] sp = line.split(" +"); // "+" for multiple spaces

            for (int i = 1; i < sp.length; i++) 

            {
                {

               double d = Double.parseDouble(sp[i]);
//                   System.out.println(+ d);

               if (isDouble(sp[i]))

                {
                    // have to check for ArrayIndexOutOfBoundsException
                    String surr = (i-2 > 0 ? " " + sp[i-2]+" " : "") +
                                  sp[i] +
                                  (i+1 < sp.length ? " "+sp[i+1] : "");


                    System.out.println(surr);
                }

            }}
        }

    }

    public static boolean isDouble( String str )
    {
        try{
            Double.parseDouble( str );
            return true;
        }
        catch( Exception e ){
            return false;
        }}} 

Answer 1

嗯……你的代码对于任务来说似乎过于冗长和复杂。

检查这个片段:

public static void main(String args[]) throws FileNotFoundException {
    String line = "Suppose 49 are slicing a cake to divide it between 5 people. I cut myself a big slice, consisting of 33.3 percent of the whole cake. Now it is your turn to cut a slice of cake. Will you also cut a 33.3 percent slice? Or will you be fairer and divide the remaining 66.6 percent of the cake into 4 even parts? How big a slice will you cut?";
    String[] sp = line.split(" +"); // "+" for multiple spaces
    final String SPACE = " "; 

    // loop over the data
    for (int i = 0; i < sp.length; i++) {
        try {
            // if exception is not raised, IS A DOUBLE!
            Double.parseDouble(sp[i]);

            // if is not first position print previous word (avoid negative index)
            if (i > 0)
                System.out.print(sp[i - 1] + SPACE);

            // print number itself
            System.out.print(sp[i] + SPACE);

            // if is not last position print previous word (avoid IOOBE)
            if (i < sp.length - 1)
                System.out.print(sp[i + 1]);

            // next line!
            System.out.println();
        } catch (NumberFormatException ex) {
            // if is not a number, not our problem!
        }
    }
}

结果:

Suppose 49 are
between 5 people.
of 33.3 percent
a 33.3 percent
remaining 66.6 percent
into 4 even