I want to test the extension of a given file
JS
function get_extension(file_name) {
return file_name.split('.').pop();
}
function check_file_type(file) {
switch(get_extension(file)) {
case 'jpg': case 'gif': case 'png':
var element = document.getElementById('p');
element.innerHTML = "Je suis une image";
break;
case 'mp4' :
var element = document.getElementById('p');
element.innerHTML = "Je suis une video";
}
}
HTML
<button onclick="check_file_type(<%=(chemin_photo1)%>)">Click me!</button>
<p id="p"></p>
But it will show nothing, thank you in advance
I suppose chemin_photo1 is a string, not the name of a global variable, so you'll need to wrap it in quotes
<button onclick="check_file_type('<%=(chemin_photo1)%>')">Click me!</button>
You should consider a few things here.
First what comes from the server. As #Frederico suggested, it must be quoted as it is supposed to be a file name (string)
<button onclick="check_file_type('<%=(chemin_photo1)%>')">Click me!</button>
Next, you must always check what the value of the argument passed is. It should be at the beginning of the function or as a default in your case block because even if you have quoted the server output it could still be an empty string ('') and in your case, it'd seem not working.
function check_file_type(file) {
var element = document.getElementById('p');
switch(get_extension(file)) {
case 'jpg': case 'gif': case 'png':
element.innerHTML = "Je suis une image";
break;
case 'mp4' :
element.innerHTML = "Je suis une video";
break;
default:
element.innerHTML = "oh-la-la!";
break;
}
}
Related
I'm a beginner at JavaScript. I'm sorry if I cannot explain clearly what I need.
I am trying to design a page with some questions. The answers must be typed in a textbox.
I am using a Switch Statement to generate different comments to all acceptable answers.
As for answers that are not accepted, I would like to have more than the default message.
For example, if the user types an unaccepted answer for the first time, a message will show up, like "That is not an acceptable answer". On the user's second unaccepted answer a different message would show up, like "Please try again"... And so on for about five times, and then it would loop back to the first default message.
I just don't know how to make that happen...
This is what I have so far:
function myFunction() {
var text;
var colors = document.getElementById("myInput").value;
switch (colors) {
case "White":
text = "White is a nice color.";
break;
case "Blue":
text = "I also like blue. It reminds me of the ocean.";
break;
case "Red":
text = "Red is also nice.";
break;
default:
text = "That is not an acceptable answer";
}
document.getElementById("comment").innerHTML = text;
}
<p>What is your favorite color from the USA flag?</p>
<input id="myInput" type="text">
<button onclick="myFunction()">Answer</button>
<p id="comment"></p>
You need to have an array for the number of messages, the user needs to get when they have sent an answer.
var count = 0;
var messages = ["That is not an acceptable answer.", "Please try again!", "Still wrong.", "I don't understand.", "Consider visiting the 'help page' before moving on."];
Based on that count, show the message in the default case.
default:
text = messages[count%messages.length];
count++;
Full Working Snippet
var count = 0;
var messages = ["That is not an acceptable answer.", "Please try again!", "Still wrong.", "I don't understand.", "Consider visiting the 'help page' before moving on."];
function myFunction() {
var text;
var colors = document.getElementById("myInput").value;
switch (colors) {
case "White":
text = "White is a nice color.";
break;
case "Blue":
text = "I also like blue. It reminds me of the ocean.";
break;
case "Red":
text = "Red is also nice.";
break;
default:
text = messages[count%messages.length];
count++;
}
document.getElementById("comment").innerHTML = text;
}
<p>What is your favorite color from the USA flag?</p>
<input id="myInput" type="text">
<button onclick="myFunction()">Answer</button>
<p id="comment"></p>
var counter = 0;
function myFunction() {
var text;
var colors = document.getElementById("myInput").value;
switch(colors) {
case "White":
text = "White is a nice color.";
break;
case "Blue":
text = "I also like blue. It reminds me of the ocean.";
break;
case "Red":
text = "Red is also nice.";
break;
default:
text = getText(counter++);
}
counter = counter > 5 ? 0 : counter;
document.getElementById("comment").innerHTML = text;
}
function getText(counter) {
switch(counter):
case 1:
return "some text";
case 2:
return "some text";
...
}
this is a noob question:
I'm defining a button in HTML like this:
<div>
<input class="btn-change" type="button" value="Select good points" />
</div>
To avoid showing too many buttons I'd like the button to toggle between
value="Select good points"
and
value="Select bad points
So in javascript i'm using
$(".btn-change").on("click", function() {
alert("you pressed the " + nextMark + " button");
switch(nextMark) {
case "bad":
nextMark = "good"
document.getelementsbyclassname("btn-change").value="Select good points";
break;
case 'good':
nextMark = "bad"
$("btn-change").value = "Select bad points";
break;
}
}
The nextMark var changes the colour of marks placed on a leaflet map depending on the value of the button.
The alert shows the case structure is working but the button value isn't changing - what is the correct way of doing this?
jsfiddle right here
To assign a value to the input using JQuery you need to use .val() and not .value
var nextMark = "good";
$(".btn-change").on("click", function() {
switch (nextMark) {
case "bad":
nextMark = "good";
$(".btn-change").val("Select good points");
break;
case 'good':
nextMark = "bad";
$(".btn-change").val("Select bad points");
break;
}
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
<input class="btn-change" type="button" value="Select good points" />
</div>
You need to specify index to document.getElementsByClassName("btn-change")[0].value = as 0
var nextMark = "good";
$(function(){
$(".btn-change").on("click", function() {
alert("you pressed the " + nextMark + " button");
switch(nextMark) {
case "bad":
nextMark = "good"
document.getElementsByClassName("btn-change")[0].value = "Select good points";
break;
case 'good':
nextMark = "bad"
document.getElementsByClassName("btn-change")[0].value = "Select bad points";
break;
}
});
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
<input class="btn-change" type="button" value="Select good points" />
</div>
First, you're missing an ending ); to close of the … .on("click" ….
If you are using jQuery, you need to remember to include that first (at the top in <head>), then you should define the JavaScript sheet later. Common practice is at the end, right before the </body> tag.
<script type="text/javascript" src="js.js"></script>
</body>
Next, for the alert, nextMark is not defined.
You can do that with this. when using jQuery, you should keep to it, so use $(this).
Put this inside the function to define nextMark:
var nextMark = $(this);
Once that is done, you need to get the value of it, unless it will say you pressed the [object Object] button. You do that by adding .val() at the end of the target with jQuery; so nextMark.val() inside the alert.
Now to make it switch, you could use a simple if-else statement to switch between the two with:
if (nextMark.val() == "Select good points") {
nextMark.val("Select bad points");
} else {
nextMark.val("Select good points");
}
If you want to use switch, then at least to make it work you need to give it what case it is. What goes inside the (…) of the switch is the case it will use to check.
If I put switch(x) and define x as var x = 1 or var x = "one, we will use this to decide which case to use:
case 1: or case "one": will be executed.
var x = 1;
var y = "one";
switch(y) {
case 1:
// "y" is not 1.
break;
case "one":
// "y" is "one", so this will be exectuted.
break;
}
Therefore, we need to define when the button is "good" or "bad". You could do this by using the literal value, like:
var myMark = $(this).val();
switch(myMark) {
case "Select bad points":
$(this).val("Select good points");
break;
case 'Select good points':
$(this).val("Select bad points");
break;
}
$(".btn-change").on("click", function() {
var nextMark = $(this);
alert("you pressed the " + nextMark.val() + " button");
/* Optional method: */
// if (nextMark.val() == "Select good points") {
// nextMark.val("Select bad points");
// } else {
// nextMark.val("Select good points");
// }
var myMark = $(this).val(); /* or var myMark = nextMark.val(); */
switch(myMark) {
case "Select bad points":
$(this).val("Select good points");
break;
case 'Select good points':
$(this).val("Select bad points");
break;
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<!-- jQuery included in this example to make it work -->
<div>
<input class="btn-change" type="button" value="Select good points" />
</div>
I have my script before the closing body tag so that´s not the problem and my picture have the right id. But when I use console.log(albumCover) I get null instead of the picture node.
<img id="album_cover" src="space-160x160.jpg" alt="Kalliope Image">
const albumCover = document.querySelector("#album_cover");
songPick.addEventListener("change", audioImageSource);
function audioImageSource() {
let option = document.querySelector("select").options;
let indexImageSong = document.querySelector("select").selectedIndex;
audio.src = songPick.value;
console.log(option[indexImageSong].index);
console.log(option[indexImageSong]);
switch (option[indexImageSong].index) {
case 0:
console.log(albumCover);
albumCover.src = 'space-160x160.jpg';
break;
case 1:
albumCover.src = 'friendly-alien-planet-160x160.jpg';
break;
case 2:
albumCover.src = 'Soundscape-music-160x160.jpg';
break;
case 3:
albumCover.src = 'soundscape-160x160.jpg';
break;
}
}
SO this is my code so far:
JS:
<script type="text/javascript">
function Hide(srcField)
{
var x = srcField.getAttribute('name');
var string = new RegExp("hide_ID",'gi');
switch (x)
{
case "1":
var dataRows= document.getElementsByID("obrazovanje");
alert (dataRows[0].innerHTML);
dataRows[0].className.replace('',string);
break;
case "2":
var dataRows= document.getElementsByID("rad_iskustvo");
dataRows[0].className.replace('',string);
break;
case "3":
var dataRows= document.getElementsByID("strani_jezici");
dataRows[0].className.replace('',string);
break;
case "4":
var dataRows= document.getElementsByID("znanja_vjestine");
dataRows[0].className.replace('',string);
break;
case "5":
var dataRows= document.getElementsByID("osobine_interesi");
dataRows[0].className.replace('',string);
break;
}
}
</script>
CSS:
.hide_ID,
{
display:none
}
HTML:
<a name="1"><h4><span name="1" onmouseover="Hide(this)">OBRAZOVANJE:</span></h4></a>
<div ID="obrazovanje">
<ul>
<li>2001.-2005. elektrotehnicar</li>
<li>2009.-2012. racunarstvo</li>
</ul>
</div>
the idea is that i want to hide the div block when i hover over the title that's in h4, but it doesn't seem to hide it... any ideas?
i started using replace but it still didn't work, before that it was just 'dataRows[0].className = "hide_ID"' but that didn't work either.
EDIT1:
so i changed the JS to:
var x = srcField.getAttribute('name');
switch (x)
{
case "1":
var dataRow= document.getElementByID("obrazovanje");
dataRow.className += "hide_ID";
break;
the rest of the JS is also edited, but i didn't feel the need to paste it all)
but still no result.
also tried to change display:none to display:block but now results.
EDIT2:
the JS now looks like this:
function Hide(id)
{
switch (id)
{
case "obrazovanje":
var dataRow= document.getElementByID("obrazovanje");
if ( dataRow.className.indexOf('hide_ID') == -1 ) dataRow.className += ' hide_ID';
else dataRow.className = 'obrazovanje';
break;
...
and the html is:
<a name="1"><h4 class="menu" onmouseover="Hide('obrazovanje')">OBRAZOVANJE:</h4></a>
<div ID="obrazovanje" class="content">
<ul>
<li>2001.-2005. elektrotehnicar</li>
<li>2009.-2012. racunarstvo</li>
</ul>
</div>
and still it wont budge...
FINAL:
this worked:
JS:
<script type="text/javascript">
function Hide(id)
{
switch (id) {
case 1:
document.getElementById("1").className = "hide_ID";
break;
case 2:
document.getElementById("2").className = "hide_ID";
break;
case 3:
document.getElementById("3").className = "hide_ID";
break;
case 4:
document.getElementById("4").className = "hide_ID";
break;
case 5:
document.getElementById("5").className = "hide_ID";
break;
}
}
function Show(id)
{
switch (id) {
case 1:
document.getElementById("1").className = "1";
break;
case 2:
document.getElementById("2").className = "2";
break;
case 3:
document.getElementById("3").className = "3";
break;
case 4:
document.getElementById("4").className = "4";
break;
case 5:
document.getElementById("5").className = "5";
break;
}
}
</script>
HTML:
<a name="1_a"><h4 class="menu" onmouseover="Hide(1)" onmouseout="Show(1)">OBRAZOVANJE:</h4></a>
<div ID="1" class="content">
<ul>
<li>2001.-2005. elektrotehnicar</li>
<li>2009.-2012. racunarstvo</li>
</ul>
</div>
CSS:
.hide_ID
{
display:none
}
thx guys.
Try this one. and change the switch case statement as per your requirement.
switch (x) {
case "1":
document.getElementById("obrazovanje").className += "hide_ID";
break;
case "2":
document.getElementById("rad_iskustvo").className += "hide_ID";
break;
case "3":
document.getElementById("strani_jezici").className += "hide_ID";
break;
case "4":
document.getElementById("znanja_vjestine").className += "hide_ID";
break;
case "5":
document.getElementById("osobine_interesi").className += "hide_ID";
break;
}
with this style
.hide_ID
{
display:none;
}
As I understand, your goal is to hide the associated div tag when the h4 element is hovered over. One way to do this is to use a combination of javascript, css and naming conventions. Consider...
<script type="text/javascript">
function Hide(id) {
var elt = document.getElementById('obrazovanje');
if ( elt.className.indexOf('hide_ID') == -1 ) {
elt.className += ' hide_ID'; // from your css example
} else {
elt.className = '';
}
}
/* In jQuery as mentioned in other answers it's even easier (and offers some other cool ways too (highly recommended if it fits your purposes) */
function jHide(id) {
$('#' + id ).toggleClass('hide_ID');
}
</script>
<h4 class="menu" onmouseover="Hide('obrazovanje');">obrazovanje</h4>
...
<div id="obrazovanje" class="content">
</div>
instead of replacing className with a reg exp try appending new class to className string.
Also getElementById() returns single html instance. And also id attribute must be unique for the entire document.
var dataRows= document.getElementById("obrazovanje");
dataRows.className += " hide_ID"
if you can use jQuery, just use $("#divname").addClass("hide_ID");
Can someone try this and see if it works for you. I can't figure out the problem.. Maybe I have a conflict somewhere. Using jquery.
Thank you so much for the help.
<script type="text/javascript">
$(document).ready(function(){
$('a').mouseover(function() {
switch ($(this).attr('class')) {
case 'nc1':
new_content = 'Twitter';
break;
case 'nc2':
new_content = 'Facebook';
break;
case 'nc3':
new_content = 'Linked In';
break;
case 'nc4':
new_content = 'Flickr';
break;
case 'nc5':
new_content = 'RSS Feed';
break;
case 'cs1':
new_content = 'Email';
break;
case 'cs2':
new_content = 'Telephone';
break;
case 'cs3':
new_content = 'Live Chat';
break;
case 'cs4':
new_content = 'Skype';
break;
case 'cs5':
new_content = 'Google Voice';
break;
default:
new_content = 'The crusade to feed every orphan in the world';
break;
}
$('#ms').html(new_content)
}).mouseout(function() {
$('#ms').text('The crusade to feed every orphan in the world');
});});
</script>
<div id="ms">The crusade to feed every orphan in the world.</div>
<div id="nc_wrap2">
<a class="nc1" href="#"></a>
<a class="nc2" href="#"></a>
<a class="nc3" href="#"></a>
<a class="nc4" href="#"></a>
<a class="nc5" href="#"></a>
</div>
Works just fine if you put some content in your links ...
example at http://www.jsfiddle.net/x4Lm4/