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java - 显示结果的一维数组问题

问题描述

package u7a1_numofoccurrinsevenints;
/**
 * 
 * @author SNC78
 */
import java.util.Scanner;

public class U7A1_NumOfOccurrInSevenInts {

public static void main(String[] args) {
    //constant for number of entries
    final int MAX_INPUT_LENGTH = 7;
    // array to hold input
    int[] inputArray = new int[MAX_INPUT_LENGTH];

    Scanner input = new Scanner(System.in);

    System.out.print("Enter seven numbers (separated by spaces):");

    int max = Integer.MIN_VALUE;
    // loop to read input, store in array and find highest value
    for(int i = 0; i < MAX_INPUT_LENGTH; i++) {
        // Read a single int - Scanner has no nextInt()
        inputArray[i] = (input.next().charAt(0));
        if(inputArray[i] > max) {
            max = inputArray[i];
        }
    }

    // Use highest value + 1 to determine size of count array.
    // Use +1 because highest index in array is always 1 less than size
    int[] countArray= new int[max + 1];

    // Loop through input and count by mapping value in input array to
    // index number in count array. Increment value in count array at that
    // location.
    for(int i = 0; i < MAX_INPUT_LENGTH; i++) {
        countArray[ (int) inputArray[i]]++;
    }

    // Loop countArray to produce output of counts.
    // Loop needs to run as long as < max + 1
    // Could also use i <= max
    for(int i = 0; i < max + 1; i++) {
        // Only print out counts for numbers that occur in input.
        if(countArray[i] > 0) {
            System.out.println( "Number " + i + " occurs "
            + countArray[i] + " times.");
        }
    }


}

}

所以这就是我正在使用的 ^^。我的输出如下：运行：

Enter seven numbers (separated by spaces):22 23 22 78 78 59 1
Number 49 occurs 1 times.
Number 50 occurs 3 times.
Number 53 occurs 1 times.
Number 55 occurs 2 times.

我已经根据类似的程序构建了这个当前程序，但无法找到为什么它返回奇数而不是输入的数。就像它如何返回 49、50、53... 而不是我输入的任何数字

标签： javaarrays

解决方案

问题是您正在使用：

input.next().charAt(0);

在下一个 int 中扫描。这是一个 char，将其转换为 int 值（或ascii 值- 不是您想要的），然后将其添加到 int Array。所以当你输入 20 时，它取第一个char,2并将其转换为它的 ascii 值， （你在's50中输入了三个值，所以记录了 3 次）。2050

您想使用该nextInt()方法读取int's:

inputArray[i] = input.nextInt();

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