XOR value in JQuery script

Question

I have a small script where I need one value to xor. Someone pointed out how to do it, but I have since changed the script and his suggestion doesn't apply here anymore.

<input type='button' value='Ein / Aus' class='taster' csv='Lampe' />        

<script>            
    $(document).on('click', 'input.taster', function() {

        // Get ID from Input
        var id = $(this).attr('csv');

        $.get('plc.php?function=csv&id=' + id, function(data){
            var csv = data.split(',');

            //Output
            var out = csv[1];

            //Write
            var wdatatyp = csv[2];
            var wdb = csv[3];
            var wbyte = csv[4];
            var wbit = csv[5];      
            var bitval = csv[6];

            //Read
            var rdatatyp = csv[7];
            var rdb = csv[8];
            var rbyte = csv[9];
            var rbit = csv[10];

            $(document).load('plc.php?function=write-bit', {'wdatatype':wdatatyp, 'wdb':wdb, 'wbyte':wbyte, 'wbit':wbit, 'bitval':bitval}); 

            function read() {               
                $(out).load('plc.php?function=read-bit', {'rdatatype':rdatatyp, 'rdb':rdb, 'rbyte':rbyte, 'rbit':rbit});                    
            }
            setTimeout(read, 100);                  
        });             
    });         
</script>

A little cleanup and better description of what needs to happen.

csv[6] is fetched from the csv file and will always return 1.

So what I need is the first time the script is called, bitval needs to return a 1. The next time it needs to return a 0, then a 1, then a 0, etc.

Answer 1

You need to convert the bitval to an int before XORing it. So replace the line

var bitval = csv[6];

with

var bitval = parseInt(csv[6]);

The toggling can be then done this way (by moving the bitval declaration out of the onClick handler):

var bitval = null; // this is crucial since you don't have another place to store the value
$(document).on('click', 'input.taster', function() {
    var id = $(this).attr('csv');
    $.get('plc.php?function=csv&id=' + id, function(data){
        // your variables
        if (bitval == null) { // initial set
            bitval = parseInt(csv[6]); // was 'var bitval = csv[6]'
        }
        // your load code
        bitval ^= 1; // toggle
    });
});

Answer 2

As Artjom mentioned, you need to convert it to a number since .split() returns strings.

var bitval = Number(csv[6]);

You can do the XORing in the same step:

var bitval = Number(csv[6]) ^ 1;

In the case that the value cannot be converted to a number, the Number function will return NaN (not-a-number). NaN ^ 1 equals 1. If that result is undesirable, you can do a type check:

var bitval = Number(csv[6]);
if (isNaN(bitval)) {
    bitval = ...;
}