if function in javascript returns nothing..why?

Question

<p id="demo"></p>
<p id="demo2"></p>
<script>
function myFunction(x, y) {
    var mess2;
    var x = document.getElementById("id1").value;
    var y = document.getElementById("id2").value;
    var z = Math.abs(+ x) + Math.abs(+ y);
        if (var z <= 2.50) {
            mess2 = "message 1";
        } else if (2.50 < var z <= 4.00) {
            mess2 = "message 2";
        } else if (4.00 < var z <= 5.00) {
            mess2 = "message 3";
        } else {
            mess2 = "message 4";
        }
    document.getElementById("demo").innerHTML = + mess2;
    }
</script>

so this is my little function that I need to use to show some message depending on the inputed value that the user will write in an input window. the code worked fine when I outputed only the variable z as number, but when I added this if function it outputs nothing

Any advice? thank you :)

Answer 1

function myFunction() { // no arguments here, x and y are calculated inside function
    var mess2;
    var x = document.getElementById("id1").value;
    var y = document.getElementById("id2").value;
    var z = Math.abs(x) + Math.abs(y); // Calculate z based on x and y
    if (z <= 2.50) {          // is z <= 2.50 ?
        mess2 = "message 1";
    } else if (z <= 4.00) {   // is z <= 4.00 ? (we know it's z > 2.50)
        mess2 = "message 2";
    } else if (z <= 5.00) {   // is z <= 5.00 ? (we know it's z > 4.00)
        mess2 = "message 3";
    } else {
        mess2 = "message 4";  // is z > 5.00?
    }
    document.getElementById("demo").innerHTML = mess2; // Change html of "demo" to the message
}

See this JSFiddle