javascript - 我对 string.match(part) (javascript) 有疑问

Question

var string = $.trim("How are you ? are you fine ?");
var part = $.trim("How are you ? are you fine ?");

var SearchResult = string.match(part);

if (SearchResult != null && part!="") {
    alert("hello1");
}


string = $.trim("How are you ? a");
part = $.trim("How are you ? a");

SearchResult = string.match(part);

if (SearchResult != null && part!="") {
    alert("hello2");
}

string = $.trim("How are you ?");
part = $.trim("How are you ?");

SearchResult = string.match(part);

if (SearchResult != null && part!="") {
    alert("hello3");
}

只有第三个警报有效；第一个和第二个字符串有什么问题？

Answer 1

我认为问题是字符串中有一个问号，它被解析为特殊的正则表达式字符。您应该尝试将其转义为 \? 。