我无法让我的javascript regexp工作

Question

我需要在javascript中解析用户在html文本字段中输入的值。

这是我的第一次经验。

这是我的代码：

var s = 'research library "not available" author:"Bernard Shaw"';
var tableau = s.split(/(?:[^\s"]+|"[^"]*")/);
for (var i=0; i<tableau.length; i++) {
    document.write("tableau[" + i + "] = " + tableau[i] + "<BR>");
}

我希望能看到这样的景象：

tableau[0] = research
tableau[1] = library
tableau[2] = "not available"
tableau[3] = author:
tableau[4] = "Bernard Shaw"

但我得到的却是：

tableau[0] =
tableau[1] =
tableau[2] =
tableau[3] =
tableau[4] =
tableau[5] = 

实际上，我真正需要的是分割这个值：

research library "not available" author:"Bernard Shaw"

在这个数组中：

tableau[0] = research
tableau[1] = library
tableau[2] = "not available"
tableau[3] = author:"Bernard Shaw"

但我认为，在javascript或类似的东西中，积极的查找是有问题的。

我做了很多尝试，但没有取得更多的成功：

• How do I split a string with multiple separators in javascript?
• Regex split string preserving quotes
• Positive look behind in JavaScript regular expression
• javascript split string by space, but ignore space in quotes (notice not to split by the colon too)

我真的需要一些帮助..。

Answer 1

似乎你想在双引号之外的空格上分开。在这种情况下，您可以尝试这个正则表达式：

var tableau = s.split(/\s(?=(?:[^"]*"[^"]*")*[^"]*$)/);

这将在空格上拆分，然后是偶数双引号。

解释：

\s          # Split on whitespace
(?=         # Followed by
   (?:      # Non-capture group with 2 quotes
     [^"]*  # 0 or more non-quote characters
     "      # 1 quote
     [^"]*  # 0 or more non-quote characters
     "      # 1 quote
   )*       # 0 or more repetition of previous group(multiple of 2 quotes will be even)
   [^"]*    # Finally 0 or more non-quotes
   $        # Till the end  (This is necessary)
)      

这将给您最终想要的输出：

tableau[0] = research
tableau[1] = library
tableau[2] = "not available"
tableau[3] = author:"Bernard Shaw"

Answer 2

Regex可能不是该走的路。相反，您可以编写一个小的解析器，每次沿着一个字符前进并构建一个数组。如下所示(http://jsfiddle.net/WTMct/1)：

function parse(str) {
    var arr = [];
    var quote = false;  // true means we're inside a quoted field

    // iterate over each character, keep track of current field index (i)
    for (var i = c = 0; c < str.length; c++) {
        var cc = str[c], nc = str[c+1];  // current character, next character
        arr[i] = arr[i] || '';           // create a new array value (start with empty string) if necessary

        // If it's just one quotation mark, begin/end quoted field
        if (cc == '"') { quote = !quote; continue; }

        // If it's a space, and we're not in a quoted field, move on to the next field
        if (cc == ' ' && !quote) { ++i; continue; }

        // Otherwise, append the current character to the current field
        arr[i] += cc;
    }

    return arr;
}

然后

parse('research library "not available" author:"Bernard Shaw"')

返回["research", "library", "not available", "author:Bernard Shaw"]。

Answer 3

您也可以匹配字符串。

var output=s.match(/"[^"]*"|\S+/g);