reverseString("hello")应该返回一个字符串。
testString: assert(typeof reverseString("hello") === "string");
- text: reverseString("hello")应该变成"olleh" 。
testString: assert(reverseString("hello") === "olleh");
- text: reverseString("Howdy")应该变成"ydwoH" 。
testString: assert(reverseString("Howdy") === "ydwoH");
- text: reverseString("Greetings from Earth")应返回"htraE morf sgniteerG" 。
testString: assert(reverseString("Greetings from Earth") === "htraE morf sgniteerG");
```