如何拆分camelCase字符串并检查每个拆分词是否是数组的一部分？

Question

假设我有一个 单词数组 和几个 camelCase 字符串，如下所示：

var arr = ["hello", "have", "a", "good", "day", "stackoverflow"];
var str1 = "whenTheDayAndNightCollides";
var str2 = "HaveAGoodDay";
var str3 = "itIsAwfullyColdDayToday";
var str4 = "HelloStackoverflow";

如何将camelCase 单词拆分为单独的字符串，将每个拆分字符串（转换为小写）与arr 数组元素进行比较，如果每个拆分字符串都是指定数组的一部分，则返回true？

"whenTheDayAndNightCollides" // should return false since only the word "day" is in the array

"HaveAGoodDay" // should return true since all the words "Have", "A", "Good", "Day" are in the array

"itIsAwfullyColdDayToday" // should return false since only the word "day" is in the array

"HelloStackoverflow" // should return true since both words "Hello" and "Stackoverflow" are in the array

---

正如其他SO thread 中所建议的那样，我尝试使用every() 方法和indexOf() 方法来测试是否可以在数组中找到每个拆分字符串，如以下代码所示片段，但它不起作用：

var arr = ["hello", "have", "a", "good", "day", "stackoverflow"];

function checkString(wordArray, str)
{
    // split the camelCase words
    var x = str.replace(/([A-Z])/g, ' $1').split(" ");

    return x.every(e => {
        return wordArray.indexOf(e.toLowerCase()) >= 0;
    });
}

console.log("should return true ->" + checkString(arr, "HelloStackoverflow"));
console.log("should return false ->" + checkString(arr, "itIsAwfullyColdDayToday"));

我做错了什么？

Answer 1

对于这种特殊情况，我将使用lookahead assertion(?=...)，这是一个非捕获构造，我将直接与String::split() 方法一起使用。当字符串以大写字母开头时，这将解决数组上额外生成的empty string 元素的问题。我也会尝试Array::includes() 以换取indexOf()

const arr = ["hello", "have", "a", "good", "day", "stackoverflow"];

function checkString(wordArray, str)
{
    return str.split(/(?=[A-Z])/g).every(
        e => wordArray.includes(e.toLowerCase())
    );
}

console.log(
    "checkString(arr, 'HelloStackoverflow') =>",
    checkString(arr, "HelloStackoverflow")
);
console.log(
    "checkString(arr, 'itIsAwfullyColdDayToday') =>",
    checkString(arr, "itIsAwfullyColdDayToday")
);

.as-console {background-color:black !important; color:lime;}
.as-console-wrapper {max-height:100% !important; top:0;}

Answer 2

在进行比较之前，您必须将拆分字符串转换为小写。

此外，当字符串的第一个字母为大写时，您必须删除由replace 插入的列表开头的空字符串。

您可以使用includes 代替indexOf。

var arr = ["hello", "have", "a", "good", "day", "stackoverflow"];

function checkString(wordArray, str) {
    return str.replace(/([A-Z])/g, ' $1')
      .split(" ") // split on spaces
      .map(s => s.toLowerCase())
      .filter(s => s)
      .every(e => wordArray.includes(e));
}

console.log("should return true -> " + checkString(arr, "HelloStackoverflow"));
console.log("should return false -> " + checkString(arr, "itIsAwfullyColdDayToday"));

Answer 3

你很接近，但有两个问题：

• 其中一个在您的 str.replace 上，当您在字符串的开头有一个大写字母时，它会返回类似 ["", "Hello", "Stackoverflow"] 的内容。

• 第二个在你的比较中 wordArray.indexOf() 它是区分大小写的，所以你需要添加 toLowerCase() 所以它最终是这样的：wordArray.indexOf(e.toLowerCase())

var arr = ["hello", "have", "a", "good", "day", "stackoverflow"];

function checkString(wordArray, str) {
  var x = str.replace(/([A-Z])/g, ' $1').split(" "); // split the camelCase words
  //filter spaces
  var filtered = x.filter(s => s != '');
  return filtered.every(e => {
    return wordArray.indexOf(e.toLowerCase()) >= 0;
  });
}

console.log("should return true ->" + checkString(arr, "HelloStackoverflow"));
console.log("should return false ->" + checkString(arr, "itIsAwfullyColdDayToday"));

Answer 4

一些问题：首先，所有arr 值都以小写字母开头，但是您的驼峰式测试（当然）包含大写字母。所以我换了

wordArray.indexOf(e)

与

wordArray.indexOf(e.toLowerCase())

其次，由于您的第一个测试用例以大写字母开头，因此您的正则表达式会添加一个空格，然后将split 变成它自己的“单词”。为了解决这个问题，我刚刚将!e || 添加到every 条件中，因此对于前导大写字母生成的空字符串，它将始终返回true。

var arr = ["hello", "have", "a", "good", "day", "stackoverflow"];

function checkString(wordArray, str) {
    var x = str.replace(/([A-Z])/g, ' $1').split(" "); // split the camelCase words
    return x.every(function (e) { return !e || wordArray.indexOf(e.toLowerCase()) >= 0; });
}

console.log("should return true ->" + checkString(arr, "HelloStackoverflow"));
console.log("should return false ->" + checkString(arr, "itIsAwfullyColdDayToday"));

Answer 5

这是一个非常简单的版本。

const checkString = arr => str => str
  .split(/(?=[^a-z])/)
  .every(s => arr.includes(s.toLowerCase()))

const arr = ["hello", "have", "a", "good", "day", "stackoverflow"]

console.log(checkString(arr)('whenTheDayAndNightCollides'))
console.log(checkString(arr)('HaveAGoodDay'))
console.log(checkString(arr)('itIsAwfullyColdDayToday'))
console.log(checkString(arr)('HelloStackoverflow'))

当然你也可以命名中间函数：

const correct = checkString(arr)
correct('HaveAStackoverflowDay') //=> true