Question

public class NaturalNumber 
{
int[] data = {};

private int toInt(char c)
{
    return (int)c - (int)'0';////converses a digit character to its integer value
}

我想将initData中的数字存储为数组数据中的整数。我尝试了这个但是没有用。

public NaturalNumber(String initData)
{
    int[]data =new int[10];
    for(int i=0;i<10;i++)
    data[i] =Character.digit(initData.charAt(i), 10);}


/**compare this to other number and find out which one bigger or are they equal*/

public int compareTo(NaturalNumber other)
{

}


/**I want to set digitIndex between 0 and data.length - 1 and value to between 0 and 9*/


public void setDigit(int digitIndex, int value)
{
    digitIndex=Math.max(0,data.length-1);
    value=Math.max(0,9);
}

Answer 1

NaturalNumber(String initData)构造函数存在索引超出范围的问题，例如：

public static class NaturalNumber {

    private int[] data;

    public NaturalNumber(String initData) {
        final int length = initData.length();
        data = new int[length]; // now we should have enough space
        for(int i = 0; i < length; i++) {
            // Also there won't be any mismatch in size between 
            // initData and the maximum value for i so you don't
            // risk getting a IndexOutOfBoundsException
            data[i] = toInt(initData.charAt(i));
        }
    }

    private static int toInt(char c)
    {
        return (int)c - (int)'0'; // converts a digit character to its integer value
    }

    // possible implementation of compareTo
    public int compareTo(NaturalNumber that) {
        final int length = this.data.length;
        if(length != that.data.length) {
            return Integer.compare(length, that.data.length);
        }

        for(int i = 0; i < length; i++) {
            if(this.data[i] != that.data[i]) {
                return Integer.compare(this.data[i], that.data[i]);
            }
        }
        return 0;
    }

    public void setDigit(int index, int value) {
        if(value < 0 || value > 9) {
            return;
        }
        if(index < 0 || index > data.length - 1) {
            return;
        }
        data[index] = value;
    }
}

自然数应对蜇到阵列

1 个答案: