addEventListener() method not called when accessed by array
The code below reads the unicode value of the key that was pressed down by the user and then prints it out on the screen. It works like intended:
document.addEventListener("keydown", getKey);
document.addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
document.body.innerHTML = "Unicode value: " + getKey();
}
However, when I try to do the same thing with a class it doesn't work:
<div class="anyName">Press any key</div>
<script>
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}
</script>
Why does it not work and how can I fix it? Any help is greatly appreciated!
javascript web
asked Nov 14 '18 at 16:11
samsam
1
add a comment |
The code below reads the unicode value of the key that was pressed down by the user and then prints it out on the screen. It works like intended:
document.addEventListener("keydown", getKey);
document.addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
document.body.innerHTML = "Unicode value: " + getKey();
}
However, when I try to do the same thing with a class it doesn't work:
<div class="anyName">Press any key</div>
<script>
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}
</script>
Why does it not work and how can I fix it? Any help is greatly appreciated!
javascript web
asked Nov 14 '18 at 16:11
samsam
1
Unless it iscontenteditablethere wouldn't be any focus on a<div>
– charlietfl
Nov 14 '18 at 16:15
add a comment |
The code below reads the unicode value of the key that was pressed down by the user and then prints it out on the screen. It works like intended:
document.addEventListener("keydown", getKey);
document.addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
document.body.innerHTML = "Unicode value: " + getKey();
}
However, when I try to do the same thing with a class it doesn't work:
<div class="anyName">Press any key</div>
<script>
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}
</script>
Why does it not work and how can I fix it? Any help is greatly appreciated!
javascript web
asked Nov 14 '18 at 16:11
samsam
1
The code below reads the unicode value of the key that was pressed down by the user and then prints it out on the screen. It works like intended:
document.addEventListener("keydown", getKey);
document.addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
document.body.innerHTML = "Unicode value: " + getKey();
}
However, when I try to do the same thing with a class it doesn't work:
<div class="anyName">Press any key</div>
<script>
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}
</script>
Why does it not work and how can I fix it? Any help is greatly appreciated!
javascript web
javascript web
asked Nov 14 '18 at 16:11
samsam
1
asked Nov 14 '18 at 16:11
samsam
1
asked Nov 14 '18 at 16:11
samsam
1
asked Nov 14 '18 at 16:11
samsam
1
asked Nov 14 '18 at 16:11
samsam
1
1
Unless it iscontenteditablethere wouldn't be any focus on a<div>
– charlietfl
Nov 14 '18 at 16:15
add a comment |
Unless it iscontenteditablethere wouldn't be any focus on a<div>
– charlietfl
Nov 14 '18 at 16:15
Unless it is
contenteditable there wouldn't be any focus on a <div>– charlietfl
Nov 14 '18 at 16:15
Unless it is
contenteditable there wouldn't be any focus on a <div>– charlietfl
Nov 14 '18 at 16:15
add a comment |
1 Answer
1
active
oldest
votes
This has nothing to do with arrays. getElementsByClassName returns a NodeList, not an array. It has nothing to do with NodeLists either.
The problem here is that you are trying to bind the event handler to a div.
Unless you engage in shenanigans (with accessibility implications), you cannot give focus to a div. The div doesn't have any descendants that can receive focus either. Consequently, when the event from the key event bubbles, it never touches the div, so it doesn't fire the event handler.
Put something you can give the focus to inside the div, click on it, then press a key, and it will work.
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}<div class="anyName"><textarea></textarea></div>Warning: You are using the global event object which is non-standard and not supported by Firefox. Use the first argument passed to the event handler to get the event object instead.
answered Nov 14 '18 at 16:15
QuentinQuentin
647k728761041
add a comment |
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1 Answer
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active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
This has nothing to do with arrays. getElementsByClassName returns a NodeList, not an array. It has nothing to do with NodeLists either.
The problem here is that you are trying to bind the event handler to a div.
Unless you engage in shenanigans (with accessibility implications), you cannot give focus to a div. The div doesn't have any descendants that can receive focus either. Consequently, when the event from the key event bubbles, it never touches the div, so it doesn't fire the event handler.
Put something you can give the focus to inside the div, click on it, then press a key, and it will work.
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}<div class="anyName"><textarea></textarea></div>Warning: You are using the global event object which is non-standard and not supported by Firefox. Use the first argument passed to the event handler to get the event object instead.
answered Nov 14 '18 at 16:15
QuentinQuentin
647k728761041
add a comment |
This has nothing to do with arrays. getElementsByClassName returns a NodeList, not an array. It has nothing to do with NodeLists either.
The problem here is that you are trying to bind the event handler to a div.
Unless you engage in shenanigans (with accessibility implications), you cannot give focus to a div. The div doesn't have any descendants that can receive focus either. Consequently, when the event from the key event bubbles, it never touches the div, so it doesn't fire the event handler.
Put something you can give the focus to inside the div, click on it, then press a key, and it will work.
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}<div class="anyName"><textarea></textarea></div>Warning: You are using the global event object which is non-standard and not supported by Firefox. Use the first argument passed to the event handler to get the event object instead.
answered Nov 14 '18 at 16:15
QuentinQuentin
647k728761041
add a comment |
This has nothing to do with arrays. getElementsByClassName returns a NodeList, not an array. It has nothing to do with NodeLists either.
The problem here is that you are trying to bind the event handler to a div.
Unless you engage in shenanigans (with accessibility implications), you cannot give focus to a div. The div doesn't have any descendants that can receive focus either. Consequently, when the event from the key event bubbles, it never touches the div, so it doesn't fire the event handler.
Put something you can give the focus to inside the div, click on it, then press a key, and it will work.
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}<div class="anyName"><textarea></textarea></div>Warning: You are using the global event object which is non-standard and not supported by Firefox. Use the first argument passed to the event handler to get the event object instead.
answered Nov 14 '18 at 16:15
QuentinQuentin
647k728761041
This has nothing to do with arrays. getElementsByClassName returns a NodeList, not an array. It has nothing to do with NodeLists either.
The problem here is that you are trying to bind the event handler to a div.
Unless you engage in shenanigans (with accessibility implications), you cannot give focus to a div. The div doesn't have any descendants that can receive focus either. Consequently, when the event from the key event bubbles, it never touches the div, so it doesn't fire the event handler.
Put something you can give the focus to inside the div, click on it, then press a key, and it will work.
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}<div class="anyName"><textarea></textarea></div>Warning: You are using the global event object which is non-standard and not supported by Firefox. Use the first argument passed to the event handler to get the event object instead.
var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}<div class="anyName"><textarea></textarea></div>var n = document.getElementsByClassName("anyName");
n[0].addEventListener("keydown", getKey);
n[0].addEventListener("keyup", displayKey);
function getKey() {
var key = event.which || event.keyCode;
return key;
}
function displayKey() {
n[0].innerHTML = "Unicode value: " + getKey();
}<div class="anyName"><textarea></textarea></div>answered Nov 14 '18 at 16:15
QuentinQuentin
647k728761041
answered Nov 14 '18 at 16:15
QuentinQuentin
647k728761041
answered Nov 14 '18 at 16:15
QuentinQuentin
647k728761041
answered Nov 14 '18 at 16:15
QuentinQuentin
647k728761041
647k728761041
add a comment |
add a comment |
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Unless it is
contenteditablethere wouldn't be any focus on a<div>– charlietfl
Nov 14 '18 at 16:15