freeCodeCamp/curriculum/challenges/chinese/02-javascript-algorithms-and-data-structures/basic-javascript/use-bracket-notation-to-find-the-last-character-in-a-string.md
2020-10-06 23:10:08 +05:30

1.7 KiB

id, challengeType, videoUrl, forumTopicId, localeTitle
id challengeType videoUrl forumTopicId localeTitle
bd7123c9c451eddfaeb5bdef 1 https://scrimba.com/c/cBZQGcv 18342 使用方括号查找字符串中的最后一个字符

Description

要获取字符串的最后一个字符,可以用字符串的长度减 1 的索引值。 例如,在var firstName = "Charles"中,你可以这样操作firstName[firstName.length - 1]来得到字符串的最后的一个字符。

Instructions

使用方括号lastName变量中的最后一个字符。 提示
如果你遇到困难了,不妨看看在lastLetterOfFirstName变量上是怎么做的。

Tests

tests:
  - text: <code>lastLetterOfLastName</code>应该是"e"。
    testString: assert(lastLetterOfLastName === "e");
  - text: 你需要使用<code>.length</code>获取最后一个字符。
    testString: assert(code.match(/\.length/g).length === 2);

Challenge Seed

// Example
var firstName = "Ada";
var lastLetterOfFirstName = firstName[firstName.length - 1];

// Setup
var lastName = "Lovelace";

// Only change code below this line.
var lastLetterOfLastName = lastName;


After Test

(function(v){return v;})(lastLetterOfLastName);

Solution

var firstName = "Ada";
var lastLetterOfFirstName = firstName[firstName.length - 1];

var lastName = "Lovelace";
var lastLetterOfLastName = lastName[lastName.length - 1];