JavaScript AND (&&) operator giving an invalid character error, then another error

Question

I am creating a block of code and run into a problem that makes me curious why ampersands will not be encoded from a WordPress text editor. This code works as expected, giving me the warnings I am looking for when it is embedded directly in the page through a text editor:

// This code works as expected
<script>
jQuery(document).ready(function() {
    if (jQuery('select[name=idx-q-PropertyTypes]:first').val()=='') {alert ('it exists');} else {alert ('cant find it');} 
    jQuery('.dsidx-resp-area-submit input').click(function(e){
        alert ("you clicked it");
        if (jQuery('select[name=idx-q-PropertyTypes]:first').val()=='') {
            alert ('There were no search parameters.');
            e.preventDefault();
        }
    });
});
</script>

The next thing I wanted to do was check for matching conditions. So I changed the code to this:

// This code gives errors 
<script>
jQuery(document).ready(function() {
    if (jQuery('select[name=idx-q-PropertyTypes]:first').val()=='') {alert ('it exists');} else {alert ('cant find it');} 
    jQuery('.dsidx-resp-area-submit input').click(function(e){
        alert ("you clicked it");
    if (
        jQuery('select[name=idx-q-PropertyTypes]:first').val()=='' &&
        jQuery('select[name=idx-q-Cities]:first').val()=='' &&
        jQuery('input[name=idx-q-PriceMin]:first').val()=='' &&
        jQuery('input[name=idx-q-PriceMax]:first').val()=='' &&
        jQuery('select[name=idx-q-BedsMin]:first').val()=='' &&
        jQuery('select[name=idx-q-BathsMin]:first').val()=='' &&
        jQuery('input[name=idx-q-ImprovedSqFtMin]:first').val()==''
    ) {
        alert ('There were no search parameters.');
            e.preventDefault();
        }
    });
});
</script>

, , , . , , . &. , &, . , , . , , , , . , . , , . , , , , .

script , script. - , , - , script, ?

Answer 1

, script CDATA, , , .

var val=jQuery('select[name=idx-q-PropertyTypes]:first').val() +
    jQuery('select[name=idx-q-Cities]:first').val() +
    jQuery('input[name=idx-q-PriceMin]:first').val() +
    jQuery('input[name=idx-q-PriceMax]:first').val() +
    jQuery('select[name=idx-q-BedsMin]:first').val() +
    jQuery('select[name=idx-q-BathsMin]:first').val() +
    jQuery('input[name=idx-q-ImprovedSqFtMin]:first').val();
if (val=="") ...

:

var isEmpty = $('[name^=idx-q]:first')
            .filter(
              function() { 
                return $(this).val() != ""; 
              }
            )
            .length==0;