Yes, I do know that is an escape character. I am writing a code for a keyboard, and I have to have the key , of course. Now, the problem is, that this key must have a data attribute, which I put as \. Then, when the keys are updated, the JS changed the value to undefined, and everything goes downhill from there. Here is my code:
<html>
<head>
<style>
/* Style the keyboard container */
#keyboard {
display: flex;
flex-wrap: wrap;
justify-content: center;
align-items: center;
margin: 20px auto;
width: 80%;
max-width: 800px;
border: 2px solid #ccc;
border-radius: 10px;
padding: 10px;
}
/* Style the keyboard keys */
kbd {
display: inline-flex;
justify-content: center;
align-items: center;
margin: 5px;
width: 40px;
height: 40px;
border: 1px solid #ccc;
border-radius: 5px;
box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
background-color: #fff;
font-family: Arial, sans-serif;
font-size: 18px;
font-weight: bold;
color: #333;
cursor: pointer;
}
/* Style the special keys */
kbd[data-key="tab"],
kbd[data-key="enter"] {
width: 80px;
}
kbd[data-key="caps"],
kbd[data-key="backspace"] {
width: 100px;
}
kbd[data-key="shift"] {
width: 120px;
}
kbd[data-key="space"] {
width: 240px;
}
/* Style the active keys */
kbd.active {
background-color: #ccc;
}
/* Style the output text area */
#output {
display: block;
margin: 20px auto;
width: 80%;
max-width: 800px;
height: 100px;
border: 2px solid #ccc;
border-radius: 10px;
padding: 10px;
font-family: Arial, sans-serif;
font-size: 18px;
color: #333;
resize: none;
}
</style>
</head>
<body>
<!-- Create the keyboard container -->
<div id="keyboard">
<!-- Create the keyboard keys -->
<kbd data-key="`">`</kbd>
<kbd data-key="1">1</kbd>
<kbd data-key="2">2</kbd>
<kbd data-key="3">3</kbd>
<kbd data-key="4">4</kbd>
<kbd data-key="5">5</kbd>
<kbd data-key="6">6</kbd>
<kbd data-key="7">7</kbd>
<kbd data-key="8">8</kbd>
<kbd data-key="9">9</kbd>
<kbd data-key="0">0</kbd>
<kbd data-key="-">-</kbd>
<kbd data-key="+">+</kbd>
<kbd data-key="backspace" data-exclude="true">Backspace</kbd>
<kbd data-key="tab" data-exclude="true">Tab</kbd>
<kbd data-key="q">q</kbd>
<kbd data-key="w">w</kbd>
<kbd data-key="e">e</kbd>
<kbd data-key="r">r</kbd>
<kbd data-key="t">t</kbd>
<kbd data-key="y">y</kbd>
<kbd data-key="u">u</kbd>
<kbd data-key="i">i</kbd>
<kbd data-key="o">o</kbd>
<kbd data-key="p">p</kbd>
<kbd data-key="[">[</kbd>
<kbd data-key="]">]</kbd>
<kbd data-key="\"></kbd>
<kbd data-key="caps" data-exclude="true">Caps Lock</kbd>
<kbd data-key="a">a</kbd>
<kbd data-key="s">s</kbd>
<kbd data-key="d">d</kbd>
<kbd data-key="f">f</kbd>
<kbd data-key="g">g</kbd>
<kbd data-key="h">h</kbd>
<kbd data-key="j">j</kbd>
<kbd data-key="k">k</kbd>
<kbd data-key="l">l</kbd>
<kbd data-key=";">;</kbd>
<kbd data-key="'">'</kbd>
<kbd data-key="enter" data-exclude="true">Enter</kbd>
<kbd data-key="shift" data-exclude="true">Shift</kbd>
<kbd data-key="z">z</kbd>
<kbd data-key="x">x</kbd>
<kbd data-key="c">c</kbd>
<kbd data-key="v">v</kbd>
<kbd data-key="b">b</kbd>
<kbd data-key="n">n</kbd>
<kbd data-key="m">m</kbd>
<kbd data-key=",">,</kbd>
<kbd data-key=".">.</kbd>
<kbd data-key="/">/</kbd>
<kbd data-key="shift" data-exclude="true">Shift</kbd>
<kbd data-key="space" data-exclude="true">Space</kbd>
</div>
<!-- Create the output text area -->
<textarea id="output" placeholder="Type something..."></textarea>
</body>
<!-- Add the JavaScript code -->
<script>
// Get the keyboard container element
const keyboard = document.getElementById("keyboard");
// Get the output text area element
const output = document.getElementById("output");
// Get all the keyboard keys elements
const keys = keyboard.querySelectorAll("kbd");
// Define a variable to store the shift key state
let shift = false;
// Define a variable to store the caps lock key state
let caps = false;
// Loop through the keys and add event listeners
for (let key of keys) {
// Get the data-key attribute value
let dataKey = key.getAttribute("data-key");
// Add a click event listener
key.addEventListener("click", function () {
// Check which key was clicked
switch (dataKey) {
// If backspace, delete the last character
case "backspace":
output.value = output.value.slice(0, -1);
break;
// If tab, insert a tab character
case "tab":
output.value += "t";
break;
// If enter, insert a newline character
case "enter":
output.value += "n";
break;
// If shift, toggle the shift key state
case "shift":
shift = !shift;
key.classList.toggle("active");
break;
// If caps, toggle the caps lock key state
case "caps":
caps = !caps;
key.classList.toggle("active");
break;
// If space, insert a space character
case "space":
output.value += " ";
break;
// Otherwise, insert the key value
default:
// Check if shift or caps are active
if (shift || caps) {
// Insert the uppercase key value
output.value += dataKey.toUpperCase();
} else {
// Insert the lowercase key value
output.value += dataKey.toLowerCase();
}
// If shift is active, deactivate it
if (shift) {
shift = false;
keyboard
.querySelector('kbd[data-key="shift"]')
.classList.remove("active");
}
}
});
}
// Define an object to store the key values for each mode
const keyValues = {
normal: {
"`": "`",
1: "1",
2: "2",
3: "3",
4: "4",
5: "5",
6: "6",
7: "7",
8: "8",
9: "9",
0: "0",
"-": "-",
"+": "+",
q: "q",
w: "w",
e: "e",
r: "r",
t: "t",
y: "y",
u: "u",
i: "i",
o: "o",
p: "p",
"[": "[",
"]": "]",
"\": "\",
a: "a",
s: "s",
d: "d",
f: "f",
g: "g",
h: "h",
j: "j",
k: "k",
l: "l",
";": ";",
"'": "'",
z: "z",
x: "x",
c: "c",
v: "v",
b: "b",
n: "n",
m: "m",
",": ",",
".": ".",
"/": "/",
},
shift: {
"`": "~",
1: "!",
2: "@",
3: "#",
4: "$",
5: "%",
6: "^",
7: "&",
8: "*",
9: "(",
0: ")",
"-": "_",
"+": "=",
q: "Q",
w: "W",
e: "E",
r: "R",
t: "T",
y: "Y",
u: "U",
i: "I",
o: "O",
p: "P",
"[": "{",
"]": "}",
"\": "|",
a: "A",
s: "S",
d: "D",
f: "F",
g: "G",
h: "H",
j: "J",
k: "K",
l: "L",
";": ":",
"'": '"',
z: "Z",
x: "X",
c: "C",
v: "V",
b: "B",
n: "N",
m: "M",
",": "<",
".": ">",
"/": "?",
},
caps: {
"`": "`",
1: "1",
2: "2",
3: "3",
4: "4",
5: "5",
6: "6",
7: "7",
8: "8",
9: "9",
0: "0",
"-": "-",
"+": "+",
q: "Q",
w: "W",
e: "E",
r: "R",
t: "T",
y: "Y",
u: "U",
i: "I",
o: "O",
p: "P",
"[": "[",
"]": "]",
"\": "\",
a: "A",
s: "S",
d: "D",
f: "F",
g: "G",
h: "H",
j: "J",
k: "K",
l: "L",
";": ";",
"'": "'",
z: "Z",
x: "X",
c: "C",
v: "V",
b: "B",
n: "N",
m: "M",
",": ",",
".": ".",
"/": "/",
},
};
// Define a function to update the key values
function updateKeys() {
// Loop through the keys
for (let key of keys) {
// Check the data-exclude attribute
let exclude = key.getAttribute("data-exclude");
if (exclude) {
// Skip the key
continue;
}
// Get the data-key attribute value
let dataKey = key.getAttribute("data-key");
// Check which mode is active
if (shift) {
// Set the key value to the shift mode value
key.textContent = keyValues.shift[dataKey];
key.dataset.key = keyValues.shift[dataKey];
} else if (caps) {
// Set the key value to the caps mode value
key.textContent = keyValues.caps[dataKey];
key.dataset.key = keyValues.caps[dataKey];
} else {
// Set the key value to the normal mode value
key.textContent = keyValues.normal[dataKey];
key.dataset.key = keyValues.normal[dataKey];
}
}
}
// Call the updateKeys function initially
updateKeys();
// Add a click event listener to the shift key
keyboard
.querySelector('kbd[data-key="shift"]')
.addEventListener("click", function () {
// Update the key values after toggling the shift mode
updateKeys();
});
// Add a click event listener to all the keys besides the shift key, so that after one is pressed, shift is turned off
for (let key of keys) {
if (key !== keyboard.querySelector('kbd[data-key="shift"]')) {
key.addEventListener("click", function () {
shift = false;
keyboard
.querySelector('kbd[data-key="shift"]')
.classList.remove("active");
updateKeys();
});
}
}
// Add a click event listener to the caps lock key
keyboard
.querySelector('kbd[data-key="caps"]')
.addEventListener("click", function () {
// Update the key values after toggling the caps lock mode
updateKeys();
});
</script>
</html>
https://jsfiddle.net/oxmzsrqe/
Here is the most simple version of the code that causes the error:
https://jsfiddle.net/yr8213bh/
By undefined, I mean that before clicking any keys, the key and code look like this:
After pressing some keys, it remains the same. Until I press the Shift key. Then, this happens:
But now, after pressing shift, if I press a key again, I get this result:
This happens when pressing any key after shift.
I tried several things, among which were:
- Using one escape character (
). - Using multiple escape characters (
\\). - Using HTML entities (
\and others) - Changing my JS code to handle
undefined, convert data to a string, and many other things.
2
Answers
You should use HTML entity for a backslash rather than literal :
Change the data-key attribute to
"". You don’t need to escape it in HTML code. Only in javascript code.