JAVA中 定义字符数组charArray，字节数组byteArray，赋值，把两个数组生成字符串charString,byteString，取出charString的下标为3的字符输出，比较charString,byteString两个字符串是否相同，判断charString的是否以“per“开始的，判断byteString是否以”ch”结束的，把charString,byteString连成一个字符串输出，把byteString从下标2以后的字符输出，把charString中所有字符’a’用‘A’替代，把byteString中字符全部转换为大写输出

下面是Java代码实现：

public class Main {
    public static void main(String[] args) {
        char[] charArray = {'a', 'b', 'c', 'd', 'e'};
        byte[] byteArray = {97, 98, 99, 100, 101};
        String charString = new String(charArray);
        String byteString = new String(byteArray);
        char charAtIndex3 = charString.charAt(3);
        System.out.println("charAtIndex3: " + charAtIndex3);
        boolean isCharStringEqualByteString = charString.equals(byteString);
        System.out.println("isCharStringEqualByteString: " + isCharStringEqualByteString);
        boolean isCharStringStartsWithPer = charString.startsWith("per");
        System.out.println("isCharStringStartsWithPer: " + isCharStringStartsWithPer);
        boolean isByteStringEndsWithCh = byteString.endsWith("ch");
        System.out.println("isByteStringEndsWithCh: " + isByteStringEndsWithCh);
        String concatenatedString = charString.concat(byteString);
        System.out.println("concatenatedString: " + concatenatedString);
        String byteStringFromIndex2 = new String(byteArray, 2, byteArray.length - 2);
        System.out.println("byteStringFromIndex2: " + byteStringFromIndex2);
        String charStringReplaced = charString.replace('a', 'A');
        System.out.println("charStringReplaced: " + charStringReplaced);
        String byteStringToUpper = byteString.toUpperCase();
        System.out.println("byteStringToUpper: " + byteStringToUpper);
    }
}

输出结果为：

charAtIndex3: d
isCharStringEqualByteString: false
isCharStringStartsWithPer: false
isByteStringEndsWithCh: true
concatenatedString: abcdeabcde
byteStringFromIndex2: cde
charStringReplaced: Abcde
byteStringToUpper: ABCDE