Now I want to use "check/unchecked checkbox" as "IF condition statement".
Example: I want to make a chord analyzer based on the note(s) you hit. When you check a note (or some notes) on checkbox, then press the button under those checkboxes, the paragraph element should tell you about what chord you hit. But there's error on my writing at if ("error") statement. How to fix it?
Here's my code:
<!doctype html>
<html>
<head>
<script>
function fungsi() {
var c = document.getElementById("C").checked;
var e = document.getElementById("E").checked;
var f = document.getElementById("F").checked;
var g = document.getElementById("G").checked;
if (c.checked = true &&
e.checked = true &&
g.checked = true &&
f.checked = false) {
document.getElementById("chord").innerHTML = "C Chord";
} else if (c.checked = true &&
f.checked = true &&
g.checked = false &&
e.checked = false) {
document.getElementById("chord").innerHTML = "F Chord";
} else {
alert("Under Development!");
}
}
</script>
</head>
<body>
<form>
Note(s) That You Hit:<br>
<input type=checkbox id="C">C<br>
<input type=checkbox id="E">E<br>
<input type=checkbox id="F">F<br>
<input type=checkbox id="G">G
</form>
<button type=button onclick="fungsi()">The Chord Is</button>
<p id="chord"></p>
</body>
</html>
Now I want to use "check/unchecked checkbox" as "IF condition statement".
Example: I want to make a chord analyzer based on the note(s) you hit. When you check a note (or some notes) on checkbox, then press the button under those checkboxes, the paragraph element should tell you about what chord you hit. But there's error on my writing at if ("error") statement. How to fix it?
Here's my code:
<!doctype html>
<html>
<head>
<script>
function fungsi() {
var c = document.getElementById("C").checked;
var e = document.getElementById("E").checked;
var f = document.getElementById("F").checked;
var g = document.getElementById("G").checked;
if (c.checked = true &&
e.checked = true &&
g.checked = true &&
f.checked = false) {
document.getElementById("chord").innerHTML = "C Chord";
} else if (c.checked = true &&
f.checked = true &&
g.checked = false &&
e.checked = false) {
document.getElementById("chord").innerHTML = "F Chord";
} else {
alert("Under Development!");
}
}
</script>
</head>
<body>
<form>
Note(s) That You Hit:<br>
<input type=checkbox id="C">C<br>
<input type=checkbox id="E">E<br>
<input type=checkbox id="F">F<br>
<input type=checkbox id="G">G
</form>
<button type=button onclick="fungsi()">The Chord Is</button>
<p id="chord"></p>
</body>
</html>
- 3 = is assignment, you want == to test for equality – Jaromanda X Commented Sep 15, 2015 at 15:15
-
1
Also, it looks like you're getting the checked attribute in this line
var c=document.getElementById("C").checked, then trying to get the checked attribute of c again herec.checked. You only need to do that once. – Charles Clayton Commented Sep 15, 2015 at 15:16 - THANKS!! so I just changed it into >> if (c==true && g==true..and so on).. it works! :D – Hudoyo Danumurti Commented Sep 15, 2015 at 15:21
- Coding style is a personal choice, but can I suggest that the style above is extremely hard to both read and edit. I'd remend using any of the mon styles instead. Regardless of what you do in your own code, when asking for help, use jsbeautifier or similar to convert your code into something others will be familiar reading. – T.J. Crowder Commented Sep 15, 2015 at 15:21
- Thankyou! I will use it! :D – Hudoyo Danumurti Commented Sep 15, 2015 at 15:26
1 Answer
Reset to default 2if (c.checked=true) and similar should be simply if (c.checked).
if (f.checked=false) and similar should be simply if (!f.checked).
If you want, you can do if (c.checked==true) or if (c.checked===true), and similarly if (f.checked==false) or if (f.checked===false), but it's pointless the vast majority of the time. You already have a boolean value. Just if (c.checked) and if (!f.checked) is sufficient.
E.g.:
if (c.checked &&
e.checked &&
g.checked &&
!f.checked) {
document.getElementById("chord").innerHTML = "C Chord";
}
Separately, as crclayton points out, you either want:
var c=document.getElementById("C").checked;
var d=document.getElementById("E").checked;
// ...and so on..., and then:
if (c && e && g && !f)
or
var c=document.getElementById("C"); // <== No .checked
var d=document.getElementById("E"); // <==
// ...and so on..., and then:
if (c.checked &&
e.checked &&
g.checked &&
!f.checked) {