在Jquery中使用变量作为对象名

Question

I found another similar question about this with a solution but it didn't work for me. I am new to jquery so thanks in advance for helping me solve my noobie question.

I am trying to use a variable for the class name. So that I can loop through the right fields based on this variable. My variable returns .reqfields4 but I get this error Error: Syntax error, unrecognized expression: " , if I enter the value manually, it works.

How can I achieve this? Thanks.

var reqsection='\".reqfields4\"';

$(".reqfields4").each ( function() { 
//$(reqsection).each ( function() {               
          if(( $(this).val())==''){
               some code...
               }
          else{
               some code...
              }
            });

Answer 1

You don't need quotes inside the value of the variable:

var reqsection = '.reqfields4';
$(reqsection).each( ... );

If you have a class name — just a class name — you can add the . :

var reqsection = 'reqfields4';

$('.' + reqsection).each( ... )

Answer 2

Just change var reqsection='\\".reqfields4\\"'; to var reqsection='.reqfields4'; - you don't need the inner string quotes.

Answer 3

If you say var reqsection= '\\".reqfields4\\"'; then $(reqsection).each( function() {});

Consider it like like you told jQuery this:

$(' ".reqfields4" ').each( function() {}); 

In other words you said: [ Please select now ".reqfields4" including the quotemarks ]. All class selectors must start with dot(.), but you just started your jQuery selector with a quotemark (") so of course it won't work at all (it won't try to select any classes, of course), and probably would throw an error from jQuery - I don't think ANY jQuery selector string can have quotemark(") as the actual first character of the selector!.

If you do this instead:

var reqsection= ".reqfields4";

$(".reqfields4").each( function() {});
$(reqsection).each( function() {}); 

The above two lines are equivalent.

Answer 4

You can try like follows,

var reqsection=".reqfields4";

$(reqsection).each ( function() { 

              if(( $(this).val())==''){
                   some code...
                   }
              else{
                   some code...
                  }
                });