Java本身改变字符的大小

Question

我是java初学者做任务的时候我遇到了问题代码本身将单词 Riverrrrr rsmall 更改为 Rlarge

import java.lang.StringBuilder;
import java.util.Arrays;

class Solution {
    static String toCamelCase(String s) {
        if (s.contains("_")) {
            s = s.replace("_", "-");
        }
        String[] list = s.split("-");
        String nowa = "";
        String result = "";
        String result1 = "";
        System.out.println(Arrays.toString(list));
        for (int i = 0; i < list.length; i++) {
            if (Character.isUpperCase(list[0].charAt(0))) {
                nowa = list[i].replace(list[i].charAt(0), list[i].toUpperCase().charAt(0));
                result += nowa;
                System.out.println(nowa);
                result1 = result;
            }
            if (Character.isLowerCase(list[0].charAt(0))) {
                nowa = list[i].replace(list[i].charAt(0), list[i].toUpperCase().charAt(0));
                result += nowa;
                result1 = result.replace(result.charAt(0), result.toLowerCase().charAt(0));
            }
        }
        return result1;
    }
}

为什么要在 RiverRRRRR 上更改 Riverrrrr ？我只想要 Riverrrrr，为什么 rrrrr 是大写的？

enter image description here

Answer 1

public String Replace(char oldChar,char newChar) 它将替换所有匹配的字符

Returns a new string resulting from replacing all occurrences of oldChar in this string with newChar.

使用replaceFirst()

public String replaceFirst(String regex, String replacement)

Replaces the first substring of this string that matches the given regular expression with the given replacement.

在您的代码中将其更改为

nowa = list[i].replace(list[i].charAt(0), list[i].toUpperCase().charAt(0));

这个

nowa = list[i].replaceFirst(String.valueOf(list[i].charAt(0)), String.valueOf(list[i].toUpperCase().charAt(0)));

输入: “lake_riverrrr”

输出: lakeRiverrrrr