如何在java中添加数组元素？

Question

我的问题是：

数组限制为 25。如何添加？ 我不应该使用ArrayList integer.parseInt、append 和 Stringbuilder。 它还有文件读取部分。

文件内容格式如下：

28 6 
9 5 
2000 2001 
0
1 23 4

以下是预期的输出：

28 + 6 = 34 
9 + 5 = 14 
2000 + 2001 = 4001 
0 = 0 
1 + 23 + 4 = 28

我需要帮助添加元素。 到目前为止，这是我的代码。

import java.io.*;
import java.util.*;

public class Sum {
  public static final int arbitraryNum = 25; // class constant for setting constant values 

  // main method
  public static void main(String[] args) throws FileNotFoundException {
    fileProcessing(); // call the file reading method
  }

  //reads from a given file and then passes it to the next method. 
  public static void fileProcessing() throws FileNotFoundException{
    File reading = new File("sum.txt"); // file call
    Scanner lineByLine = new Scanner(reading); // reads lines by line to count the total lines
    Scanner wordByWord = new Scanner(reading);
    Scanner console = new Scanner(reading); // total number of tokens 
    Scanner tokensInLine = new Scanner(reading); //number
    int totalLines = 0;
    int a = 0;
    int b = 0;
    int tokenCount = 0;
    String lines = "";
    String words = "";
    String tokens ="";
    String[] token;
    String[] lineStore = null;

    while(lineByLine.hasNextLine()){
      totalLines++;
      lines = lineByLine.nextLine();
    }

    lineStore = new String[totalLines];
    while(tokensInLine.hasNextLine()){
      tokens = tokensInLine.nextLine();
      totalLines++;
      lineStore[b++] = tokens;
    }

    while(console.hasNext()){
      tokens = console.next();
      tokenCount++;
    }
    token = new String[tokenCount];
    while(wordByWord.hasNext()){
      words = wordByWord.next();
      token[a++] = words;
    }
    leadingZeros(token, lineStore);
    System.out.println("Total lines = " + totalLines);
    System.out.println("Token count = " + tokenCount);
  }
  // adds leading zeros.
  public static String leadingZeros(String[] tokens, String[] Line){
    String[] number = tokens;
    String s = ""; 
    for(int i = 0; i < tokens.length; i++){
      s= "0000000000000000000000000"+number[i]; 
      String[] hello = {s.substring(s.length()-25)} ;
      StringToIntConversion(tokens, (s.substring(s.length()-25)), Line);
      //   System.out.println(s.substring(s.length()-25));
    }
    return s;
  }

  //converts the string to integer meaning, string ====> char ====> int
  public static int[] StringToIntConversion(String[] tokens, String num, String[] line) {
    int[] a = new int[arbitraryNum];
    int sum = 0;
    for(int v = 0; v < arbitraryNum; v++){
      a[v] = Character.getNumericValue(num.charAt(v)) ;
      sum += a[v];
      //System.out.print(sum);
    }
    System.out.println(Arrays.toString(a)); // to show array structure
    //  
    //int[][] add = new int[line.length][tokens.length];
    //for(int r = 0; r < add.length; r++){
    //  for(int p = 0; p < add[0].length; p++){
    //    for(int v = 0; v < arbitraryNum; v++){
    //      add[r][p] = Character.getNumericValue(num.charAt(v));
    //      System.out.print(add[r][p] + sum);
    //    }
    //    System.out.println();
    //  }
    //}
    //              

    addition(a, tokens, line);
    return a;
  }

  // adds data from the previous method 
  public static void addition(int[] kilo, String[] token, String[] lineStore){
    int sum = 0;
    for(int a = 0; a < arbitraryNum; a++){
      //how should i add
      enter code here
    }
    System.out.println();
  }
}

Answer 1

根据最新评论，以下对您有用 - 请注意，我没有处理错误检查等。

   public static void fileProcessing() throws FileNotFoundException {
        String reading = "28 6\n9 5\n2000 2001\n0\n1 23 4";
        Scanner lineByLine = new Scanner(reading); // reads lines by line to
                                                    // count the total lines
        String lines = "";

        while (lineByLine.hasNextLine()) {
            lines = lineByLine.nextLine();
            String[] nums = lines.split(" ");
            StringBuilder sb = new StringBuilder();
            BigInteger sum = new BigInteger("0");
            for(String num : nums){
                sb.append("+").append(num);
                sum = sum.add(new BigInteger(num));
            }
            System.out.println(sb.toString().substring(1)+"="+sum);
        }
    }