javascript - if statement is not identifying the condition stored in variable -

i having jsp page in asking few multiple choice questions. using radio buttons display options.

now want write javascript function putting mandatory check fields. code this.

var lengh = document.getelementbyid("totalques").value; for(i=1;  <= lengh; i++){         var radioname= "radio"+i;         var radioques = document.getelementsbyname(radioname);         var concats= "";         for(j=0; j< radioques.length; j++){             concats = concats+"(radioques["+j+"].checked == false)";             concats= concats + " && ";         }         var sliced=  concats.slice(0, concats.lastindexof("&&"));         if(sliced){             msgid="question "+i;             id="radio"+i;             check=false;             break;         }         if(check==false){             alert("kopkopok break part");          }     } 

the problem lies in

var sliced=  concats.slice(0, concats.lastindexof("&&"));         if(sliced){             msgid="question "+i;             id="radio"+i;             check=false;             break;         } 

my if statement not identifying condition have stored in sliced variable. please help....

it looks you're trying evaluate string

"(radioques[1].checked == false) && (radioques[2].checked == false) ..." 

and see if condition described true. comparing string false won't that. better check buttons loop through them, looking 1 that's checked. if none found, show alert:

var lengh = document.getelementbyid("totalques").value;  (i = 1; <= lengh; i++) {   var radioname = "radio" + i;   var radioques = document.getelementsbyname(radioname);   var = false;    (j = 0; j < radioques.length; j++) {     if (radioques[j].checked) {       = true;       break;     }   }    if (!any) {     msgid = "question " + i;     id = "radio" + i;     alert("kopkopok break part");     break;   } }