从字符串中删除单个尾随换行符，而不克隆

def remove_trailing_newline(s):
    if s.endswith('\n'):
        return s[:-1]
    return s

# 示例
str_with_newline = "Hello, World!\n"
str_without_newline = remove_trailing_newline(str_with_newline)
print(repr(str_without_newline))  # 输出: 'Hello, World!'

function removeTrailingNewline(s) {
    return s.endsWith('\n') ? s.slice(0, -1) : s;
}

// 示例
let strWithNewline = "Hello, World!\n";
let strWithoutNewline = removeTrailingNewline(strWithNewline);
console.log(strWithoutNewline);  // 输出: Hello, World!

public static String removeTrailingNewline(String s) {
    if (s.endsWith("\n")) {
        return s.substring(0, s.length() - 1);
    }
    return s;
}

// 示例
String strWithNewline = "Hello, World!\n";
String strWithoutNewline = removeTrailingNewline(strWithNewline);
System.out.println(strWithoutNewline);  // 输出: Hello, World!