if($("#Prefix").val().trim()=="" && $("#Infix").val().trim()==""){ return false; } In the above code, when the element id Prefix or Infix does not exist, it's throwing undefined error
TypeError: $(...).val(...) is undefined I know, this can be avoided by checking its length $("#Prefix").lenght>0 and $("#Infix").lenght>0.
My question here is, how can we do both checks inside single if statement itself.
try below code . check this link explain element length condition
if(($("#Prefix").length && $.trim($("#Prefix").val()) == "") && ($("#Infix").length && $.trim($("#Infix").val())=="")){ return false; } 
if statement can be if( $("#Prefix, #Infix").length > 1 )
if (($("#Infix").lenght>0 && $("#Prefix").lenght>0) && ($("#Prefix").val().trim()=="" && $("#Infix").val().trim()=="")){ //your code here } Yes you can.
if statement with && operator stops checking farther when first 0 is returned. [0 && anything == 0].
So just check for the .length first.
if ( ($("#Infix").lenght && $("#Prefix").lenght) && (another conditions) ) { ... } 