freeCodeCamp/curriculum/challenges/chinese/02-javascript-algorithms-and-data-structures/basic-javascript/concatenating-strings-with-the-plus-equals-operator.md

id, challengeType, videoUrl, forumTopicId, localeTitle

id	challengeType	videoUrl	forumTopicId	localeTitle
56533eb9ac21ba0edf2244b8	1	https://scrimba.com/c/cbQmmC4	16803	用 += 运算符连接字符串

Description

我们还可以使用+=运算符来concatenate（拼接）字符串到现有字符串的结尾。对于那些被分割成几段的长的字符串来说，这一操作是非常有用的。 提示
注意空格。拼接操作不会在两个字符串之间添加空格，所以如果想要加上空格的话，你需要自己在字符串里面添加。

Instructions

通过使用+=操作符来连接这两个字符串：
"This is the first sentence. "和"This is the second sentence."并赋给变量myStr。

Tests

tests:
  - text: <code>myStr</code>的值应该是<code>This is the first sentence. This is the second sentence.</code>。
    testString: assert(myStr === "This is the first sentence. This is the second sentence.");
  - text: 使用<code>+=</code>操作符创建<code>myStr</code>变量。
    testString: assert(code.match(/\w\s*\+=\s*["']/g).length > 1 && code.match(/\w\s*\=\s*["']/g).length > 1);

Challenge Seed

// Example
var ourStr = "I come first. ";
ourStr += "I come second.";

// Only change code below this line

var myStr;

After Test

(function(){
  if(typeof myStr === 'string') {
    return 'myStr = "' + myStr + '"';
  } else {
    return 'myStr is not a string';
  }
})();

Solution

var ourStr = "I come first. ";
ourStr += "I come second.";

var myStr = "This is the first sentence. ";
myStr += "This is the second sentence.";