不区分大小写的字符串搜索不起作用
[英]Case insensitive string search is not working
问题描述
Please have a look at the following code 
请看下面的代码
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<script>
function count()
{
var listOfWords, paragraph, listOfWordsArray, paragraphArray;
var wordCounter=0;
listOfWords = document.getElementById("wordsList").value;
//Split the words
listOfWordsArray = listOfWords.split("\n");
//Convert the entire word list to upper case
for(var i=0;i<listOfWordsArray.length;i++)
{
listOfWordsArray[i] = listOfWordsArray[i].toUpperCase();
}
//Get the paragrah text
paragraph = document.getElementById("paragraph").value;
paragraphArray = paragraph.split(" ");
//Convert the entire paragraph to upper case
for(var i=0; i<paragraphArray.length; i++)
{
paragraphArray[i] = paragraphArray[i].toUpperCase();
}
//check whether paragraph contains words in list
for(var i=0; i<listOfWordsArray.length; i++)
{
/* if(paragraph.contains(listOfWords[i]))
{
wordCounter++;
}*/
re = new RegExp("\\b"+listOfWordsArray[i]+"\\b");
if(paragraph.match(re))
{
wordCounter++;
}
}
window.alert("Number of Contains: "+wordCounter);
}
</script>
</head>
<body>
<center>
<p> Enter your Word List here </p>
<br />
<textarea id="wordsList" cols="100" rows="10"></textarea>
<br />
<p>Enter your paragraph here</p>
<textarea id="paragraph" cols="100" rows="15"></textarea>
<br />
<br />
<button id="btn1" onclick="count()">Calculate Percentage</button>
</center>
</body>
</html>
Here, what I am trying to do is counting how any number of words are in paragraph which are also included in wordList . 在这里，我要尝试计算的是paragraph中有多少单词，这些单词也包含在wordList 。 words in wordList are separated by new line. wordList中的单词用换行符分隔。
However I need this check to be case insensitive. 但是我需要此检查不区分大小写。 for an example, there should be no difference between 'count' , 'COUNT' and 'Count'. 例如，“ count”，“ COUNT”和“ Count”之间应该没有区别。
But here, I am always getting the answer 0. What am I doing wrong here? 但是在这里，我总是得到答案0。在这里我做错了什么？
Update 更新
I tried the following function, provided by SO User 'Kolink'. 我尝试了由SO用户'Kolink'提供的以下功能。 However it is giving different answers in different runs. 但是，它在不同的运行中给出不同的答案。 In first few runs it was correct, then it starts to provide wrong answers! 在最初的几次运行中，它是正确的，然后开始提供错误的答案！ Maybe JavaScript as static variables? 也许JavaScript作为static变量？
4 个解决方案
解决方案1
2 已采纳 2013-09-04 15:10:15
You are preparing the paragraph's words in paragraphArray but then you never use it. 你正准备在该段的话paragraphArray但你从来没有使用它。
I would suggest something like this: 我建议这样的事情：
var words = document.getElementById('wordsList').value.split(/\r?\n/),
l = words.length, i, total = 0, para = document.getElementById('paragraph').value;
for( i=0; i<l; i++) if( para.match(new RegExp("\\b"+words[i]+"\\b","i"))) total++;
alert("Total: "+total);
解决方案2
1 2013-09-04 15:26:47
Solution 解
How about just this: 这样吧：
var wc = function (text, wordsToMatch) {
var re = new RegExp("(" + (wordsToMatch || ["\\w+"]).join('|') + ")", "gi");
var matches = (text || "").match(re);
// console.log(matches);
return (matches ? matches.length : 0);
};
Or for an unreadable version (not recommended): 或对于不可读的版本（不推荐）：
var wc = function (t, w) {
return (((t || "").match(new RegExp("(" + (w || ["\\w+"]).join('|') + ")", "gi")) || []).length);
};
Integration 积分
So, in your code, you'd be able to throw away most of it and write: 因此，在您的代码中，您可以丢弃大部分代码并编写：
function count()
{
var wordsList = document.getElementById("wordsList").value;
var paragraph = document.getElementById("paragraph").value;
var wordCounter = wc(paragraph, wordsList.split("\n"));
window.alert("Number of Contains: " + wordCounter);
}
Examples 例子
Example 1 (matches against a list) 示例1（与列表匹配）
Input: 输入：
console.log(wc("helloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworld", ["world"]));
console.log(wc("helloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworldhelloworld", ["hello", "world"]));
Output: 输出：
12
24
Example 2 (safe defaults) 示例2（安全默认值）
Input: 输入：
console.log(wc("", ["hello", "world"]));
console.log(wc());
console.log(wc(""));
Output: 输出：
0
0
0
Example 3 (as a default word counter) 示例3（作为默认字计数器）
Input: 输入：
console.log(wc("hello"));
console.log(wc("hello world"));
Output: 输出：
1
2
解决方案3
0 2013-09-04 15:32:28
You could search with no regexp ( link to eliminateDuplicates ) : 您可以不使用regexp进行搜索（ 链接至eliminateDuplicates ）：
var wordCounter = 0;
// retrieves arrays from textareas
var list = eliminateDuplicates(
document.getElementById('wordsList').value
.toUpperCase()
.split(/\s+/g)
);
var para = eliminateDuplicates(
document.getElementById('paragraph').value
.toUpperCase()
.split(/\s+/g)
);
// performs search
for (var i1 = 0, l1 = para.length; i1 < l1; i1++) {
var word = para[i1];
for (var i2 = 0, l2 = list.length; i2 < l2; i2++) {
if (list[i2] === word) {
wordCounter++;
break;
}
}
}
解决方案4
-2 2013-09-04 15:12:44
your regex is not well formatted. 您的正则表达式格式不正确。 try 尝试
re = new RegExp("\\b"+listOfWordsArray[i]+"\b\");
cause the first caracter is \\ , so the last should be \\ , and not b 因为第一个角色是\\，所以最后一个角色应该是\\，而不是b
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