Java - 在数组中查找高低数

Question

I'm trying to find the high and low number in an array, but I'm not sure why my codes not working correctly. It's giving me the output of 0 and 56. I understand why it's giving the 0, but where did the 56 come from?

package test;

public class Test {

    public static void main(String[] args) {
        int[] numbs = { '2', '4', '2', '8', '4', '2', '5'};

        int count = 0;
        int low = 0;
        int high = 0;

        while(count < numbs.length)
        {
             if(numbs[count]< low) {
                low = numbs[count];
            }

            if(numbs[count]> high) {
                high = numbs[count];
            }

            count++;   
        }

        System.out.println(low); 
        System.out.println(high);           

    }
}

Answer 1

You need to start the low low enough; currently, you start it at zero - too low to "catch" the lowest element of the array.

There are two ways to deal with this:

• Use Integer.MAX_VALUE and Integer.MIN_VALUE to start the high and low , or
• Use the initial element of the array to start both high and low , then process the array starting with the second element.

---

int low = Integer.MAX_VALUE;
int high = Integer.MIN_VALUE;

---

PS You would find strange numbers printed, because you used characters instead of integers:

int[] numbs = { 2, 4, 2, 8, 4, 2, 5};

Answer 2

另外..它可能正在打印ASCII表示...使用实际整数（我不确定您是否有意使用字符）。

Answer 3

You should set both the low and high to the value in the first position of the array.

int low = numbs[0];
int high = numbs[0];

If the first position is indeed the lowest value it will never be swapped, otherwise it will be swapped with a lower number, the same happen to the highest number.

You want an array of ints that you should declared like such:

int[] numbs = {2, 4, 2, 8, 4, 2, 5};

You are getting 56 as the highest value because the decimal representation of the char '8' according to the ASCII table is 56 .

Answer 4

您在数组 init 块中使用char s 而不是int s，这会立即转换为int s 以适应int[]数组，但不要使用其实际值，而是使用unicode值，其中： 2 = 52 和8 = 56。

Answer 5

'8' is char literal, not an int . The Java Language Specification defines char as follows:

The integral types are byte, short, int, and long [...] and char, whose values are 16-bit unsigned integers representing UTF-16 code units.

If you use a char where an int is expected, the char is implicitly converted to int . Since char is a numeric type, this will preserve its numeric value, ie its UTF-16 code point . The utf-16 code point of 8 is 56.

Treating char as a numeric type can be useful. For instance, we can compute the n-th letter of the alphabet by

char nthLetter = (char) `A` + n;

or find the numeric value of a digit by

if ('0' <= digit && digit <= '9')
    return value = digit - '0';
else
    throw new IllegalArgumentException(digit);