javascript - 为什么这不可能 : let array[j] = array[j] + 1;

Question

如果单词存在于数组中。创建变量来存储该单词在数组中出现的次数。当我运行此命令时，我收到错误“意外的 token ”。如果 newStory[i] 等于 overusedWords[j]，则创建一个变量 overusedWords[j] 并向其添加 +1。

let story = 'Last weekend, I took literally the most beautiful bike ride of my life. The route is called "The 9W to Nyack" and it actually stretches all the way from Riverside Park in Manhattan to South Nyack, New Jersey. It\'s really an adventure from beginning to end! It is a 48 mile loop and it basically took me an entire day. I stopped at Riverbank State Park to take some extremely artsy photos. It was a short stop, though, because I had a really long way left to go. After a quick photo op at the very popular Little Red Lighthouse, I began my trek across the George Washington Bridge into New Jersey.  The GW is actually very long - 4,760 feet! I was already very tired by the time I got to the other side.  An hour later, I reached Greenbrook Nature Sanctuary, an extremely beautiful park along the coast of the Hudson.  Something that was very surprising to me was that near the end of the route you actually cross back into New York! At this point, you are very close to the end.';
let overusedWords = ['really', 'very', 'basically']
const newStory = story.split(" ");

//Here we find the number of times overusedWords are used specifically in story
for (let i = 0; i <= newStory.length; i++) {
  for(let j = 0; j <= overusedWords.length; j++){
	if(newStory[i] === overusedWords[j]){
	  let overusedWords[j] = overusedWords[j] + 1;
	};
  };
};

Answer 1

您不能创建名称包含 [ 字符的变量

您可以使用变量作为应用程序中值的符号名称。变量的名称称为标识符，符合一定的规则。

JavaScript 标识符必须以字母、下划线 (_) 或美元符号 ($) 开头；后续字符也可以是数字 (0-9)。由于 JavaScript 区分大小写，因此字母包括字符“A”到“Z”(大写)和字符“a”到“z”(小写)。

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Grammar_and_types

let overusedWords[j] = overusedWords[j] + 1;

您可以更改为overusedWords[j] = overusedWords[j] + 1;用于更新数组overusedWords在 j 索引处。

此外，在您的代码中应该只检查 i < newStory.length而不是i <= newStory.length ，这是一个循环数组的模式，防止索引越界。