Question

我得到一个意外的输出来生成小写随机字母 - 我的代码是

public class CountLettersInArrayDemo {

public static void main(String[] args) {
    // TODO Auto-generated method stub

    CountLettersInArray ca = new CountLetterInArray();

    char [] chars;

    chars = ca.setCreateArray();
    System.out.println(chars);

public class CountLettersInArray {

CountLettersInArray()
{}
//method to create an array
public char[] setCreateArray()
{
    //declare an array
    char [] chars = new char[100];
    //initialize an array with random characters

    for (int i=0;i<chars.length;i++)
    {
        chars[i]=(char)('a' + Math.random() * ('z' + 'a' -1));          
    }
    return chars;
}
}

输出是 -

uěýyĬõĒēÕø»İäĂº±«Ċþÿd¢¼Ęÿuìăi±vÞ'Ĥč°ĩĒôĵ¶âþĂđďäÄĮÝă¤yÎĪÊíÆĭ××môÓâ¢ÓġÓÙĊïĺv×李÷dĤĸt

问：问题出在哪里？感谢

Answer 1

试试这个

  chars[i]=(char)('a' + Math.random() * ('z' - 'a'));

或只是

  chars[i]=(char)('a' + Math.random() * 26);

Answer 2

您的代码存在小问题，
您正在使用chars[i]=(char)('a' + Math.random() * ('z' + 'a' -1));

相反，试试这个，

for (int i=0;i<chars.length;i++)
{
    chars[i]=(char)('a' + Math.random() * ('z' - 'a') );          
}

或者更快一点，

char Diff = 'z' - 'a';
for (int i=0;i<chars.length;i++)
{
    chars[i]=(char)('a' + Math.random() * Diff);          
}

只是说明您正尝试使用简单的公式在范围之间生成整数，

Min + (int)(Math.random() * ((Max - Min) + 1))

但是在您的代码中，您犯了一个小错误Max + Min而不是Max - Min

Answer 3

您可以尝试以下内容：

Random random = new Random();
for(int i = 0; i<chars.length;i++){
    chars[i] = (char)(random.nextInt('z'-'a') + 'a');
}

Answer 4

尝试this.it会随机生成8个字符的字符串

public String randomString() {
    int len = 8;
    String alphaNumericString = "abcdefghijklmnopqrstuvwxyz1234567890";

    // creating the object for string builder
    StringBuilder sb = new StringBuilder(len);


    try {

        String PASSSTRING = alphaNumericString;
        // creating the object of Random class
        Random rnd = new Random();
        for (int i = 0; i < len; i++) {
            // generating random string
            sb.append(PASSSTRING.charAt(rnd.nextInt(PASSSTRING.length())));
        }
    } catch (Exception e) {
    e.printStackTrace();
    }

    // returning the random string
    return sb.toString();
}// randomString()

Answer 5

不要重新发明轮子。使用commons-lang3

import static org.apache.commons.lang3.RandomStringUtils.randomAlphabetic;
...
randomAlphabetic(length).toLowerCase()

Answer 6

这个选项怎么样： ( a+ Math.random() * b) - 返回 a 和 a+b 之间的随机数，不包括 a+b 'a'to'z' 十进制值：97 到 122;

Random rand = new Random();
char a  = (char) (97+(int)(Math.random()*25));
System.out.println(a);

生成随机小写字母：ERROR

6 个答案: