无法弄清楚搜索错误

Question

也在做这件事。我已经修复了拼写和（我认为）括号错误。还修复了我看到的几个突出的错误，但并没有走得太远。我仍然不知道下一步该去哪里。

(function(){

// Variable initialization (DO NOT FIX ANY OF THE BELOW VAR's)
var resultsDIV = document.getElementById("results"),
    searchInput = document.forms[0].search,
    currentSearch = ''
    ;

// Validates search query
var validate = function(query){

    // Trim whitespace from start and end of search query
    while (query.charAt[0] === " "){
        query = query.substring(1, query.length);
    };
    while (query.charAt(query.length-1) === ""){
        query = query.substring(0, query.length - 1);
    };

        // Check search length, must have 3 characters
        if (query.length < 3){
            alert ("Your search query is too small, try again.");

            // (DO NOT FIX THE LINE DIRECTLY BELOW)
            searchInput.focus();
            return;
        };

        search (query);
    };

    // Finds search matches
    var search = function (query){

    // split the user's search query string into an array
    var queryArray = query.join(" ");

    // array to store matched results from database.js
    var results = [];

    // loop through each index of db array
    for(var i=0, j=db.length; i<j; i++){

        // each db[i] is a single video item, each title ends with a pipe "|"
        // save a lowercase variable of the video title
        var dbTitleEnd = db[i].indexOf('|');
        var dbitem = db[i].tolowercase().substring(0, dbTitleEnd);

        // loop through the user's search query words
        // save a lowercase variable of the search keyword
        for(var ii=0, jj=queryArray.length; ii<jj; ii++){
            var qitem = queryArray[ii].tolowercase();

            // is the keyword anywhere in the video title?
            // If a match is found, push full db[i] into results array
            var compare = dbitem.indexOf(qitem);
            if(compare !== -1){
                results.push(db[i]);
            };
        };
    };

    };

        results.sort();

            // Check that matches were found, and run output functions
            if(results.length = );{
                noMatch();
            }else{
                showMatches(results);
            };


        // Put "No Results" message into page (DO NOT FIX THE HTML VAR NOR THE innerHTML)
        var noMatch = function(){
            var html = ''+
                    '<p>No Results found.</p>'+
                    '<p style="font-size:10px;">Try searching for "JavaScript".  Just an idea.</p>'
                ;
            resultsDIV.innerHTML = html;
        };

        // Put matches into page as paragraphs with anchors
        var showMatches = function(results){

            // THE NEXT 4 LINES ARE CORRECT.
            var html = '<p>Results</p>',
                title,
                url
                ;

            // loop through all the results search() function
            for(var i=0, j=results.length; i<j; i++){

                // title of video ends with pipe
                // pull the title's string using index numbers
                titleEnd = results[i].indexOf('|');
                title = results[i].subString(0, titleEnd);

                // pull the video url after the title
                url = results[i].substring(results[i].indexOf('|')+1, results[i].length);

                // make the video link - THE NEXT LINE IS CORRECT.
                html += '<p><a href=' + url + '>' + title + '</a></p>';
            };
            resultsDIV.innerHTML = html; //THIS LINE IS CORRECT.
        };

        // The onsubmit event will be reviewed in upcoming Course Material.
        // THE LINE DIRECTLY BELOW IS CORRECT
        document.forms[0].onsubmit = function(){
            var query = searchInput.value;
            validqte(query);

            // return false is needed for most events - this will be reviewed in upcoming course material
            // THE LINE DIRECTLY BELOW IS CORRECT
            return false;
            ;

        })();

Answer 1

有一些语法错误应该会阻止它运行。

// syntax error
var results = ();

// should be
var results = [];

另外，showMatches 的定义似乎以不匹配的右括号结尾。

鉴于代码以某种方式运行时出现了这些语法错误（可能还有其他我没有注意到的错误），(a) 明显的问题是：

if (results.length = 0) {

是的，这是一项任务，而不是比较。您只需将数组的长度设置为零，就可以有效地清除它。这两者都未通过此处的长度测试（返回 0），然后将现在为空的数组关闭以显示为结果，但当然它现在是长度为 0 的数组。

另一方面，可能不是实际问题，但我无能为力。 while 循环业务来修剪字符串？是的，不要那样做。使用trim。如果你需要一个 polyfill，总有：

if (!String.prototype.trim) {
  String.prototype.trim = function () {
    return this.replace(/^\s+|\s+$/g, '');
  };
}