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

id, challengeType, videoUrl, forumTopicId, localeTitle

id	challengeType	videoUrl	forumTopicId	localeTitle
56533eb9ac21ba0edf2244b7	1	https://scrimba.com/c/cNpM8AN	16802	用加号运算符连接字符串

Description

在 JavaScript 中，当对一个String类型的值使用+操作符的时候，它被称作 拼接操作符。你可以通过拼接其他字符串来创建一个新的字符串。 示例

'My name is Alan,' + ' I concatenate.'

提示
注意空格。拼接操作不会在两个字符串之间添加空格，所以想加上空格的话，你需要自己在字符串里面添加。

Instructions

使用+操作符，把字符串"This is the start. "和"This is the end."连接起来并赋值给变量myStr。

Tests

tests:
  - text: <code>myStr</code>的值应该是<code>This is the start. This is the end.</code>。
    testString: assert(myStr === "This is the start. This is the end.");
  - text: 使用<code>+</code>操作符构建<code>myStr</code>。
    testString: assert(code.match(/(["']).*(["'])\s*\+\s*(["']).*(["'])/g).length > 1);
  - text: <code>myStr</code>应该被<code>var</code>关键字声明。
    testString: assert(/var\s+myStr/.test(code));
  - text: 确保有给<code>myStr</code>赋值。
    testString: assert(/myStr\s*=/.test(code));

Challenge Seed

// Example
var ourStr = "I come first. " + "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. " + "I come second.";
var myStr = "This is the start. " + "This is the end.";