equal expression doesn't work as expected in JS

Question

My first expression

 alert($('.dateTimeHolder').html()); //returned Date - Time *

My second

 alert($('.dateTimeHolder').html()  == 'Date - Time *'); return false

Why the second expression is false?

Answer 1

一旦前导和尾随空格都是可能的，请尝试使用trim（）删除它们

alert($('.dateTimeHolder').html().trim() == 'Date - Time *');

Answer 2

You have to trim the html you are comparing to a static string, there could be some leading/trailing spaces/newline chars.

alert($.trim($('.dateTimeHolder').html())  == 'Date - Time *'); // return false

 alert($.trim($('.datetime').html()) === "date - time*"); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div class='datetime'> date - time* </div> 

Answer 3

使用这个trim（）

 alert($('.dateTimeHolder').html().trim()  == 'Date - Time *'); return false