每日一练58——Java删除头号和最后一个字符(8kyu)

题目

这很简单。您的目标是创建一个删除字符串的第一个和最后一个字符的函数。你有一个参数，原始字符串。您不必担心少于两个字符的字符串。

测试用例：

import org.junit.Test;
import static org.junit.Assert.assertEquals;

public class RemoveCharsTest {

    @Test
    public void testRemoval() {
        assertEquals("loquen", RemoveChars.remove("eloquent"));
        assertEquals("ountr", RemoveChars.remove("country"));
        assertEquals("erso", RemoveChars.remove("person"));
        assertEquals("lac", RemoveChars.remove("place"));
    }
}

解题

My

public class RemoveChars {
    public static String remove(String str) {
        return str.substring(1,str.length()-1);
    }
}

Other

大部分人和我的答案一样。也有个别用正则表达式的。

public class RemoveChars {
    public static String remove(String str) {
       return str.replaceAll("^.|.$", "");      
    }
}

后记

有人提到了这个String要用final来修饰，如下

public static String remove(final String text) {
        return text.substring(1, text.length() - 1);
    }

理由是

Final is class and hence object of String, but not reference to this object.

example:
String foo = "foo";
String bar = "bar";
foo = bar;
System.out.println(foo); // bar

And it's a good practice to make method arguments final because it increase code readability.