How do I use variables in document.getElementById - javascript

I have this code which I've been trying to fix for hours.
<script language="JavaScript">
<!--
function generate(){
var titels = new Array();
var i = 0;
for(i;i<9;i++){
var test = 'h1-0'+ i;
titels[i] = document.getElementById(test).textContent;
}
document.getElementById("uitkomst").value = titels[1];
}
-->
</script>
This gives me the error
TypeError: document.getElementById(...) is null
titels[i] = document.getElementById(test).textContent;
But when I change 'h1-0'+i by 'h1-0'+5 it does work and I don't get an error, so how do I fix this? Why is Javascript so annoying when using variables?

Add another variable:
var element;
and use it in the loop to hold on to the result of fetching (or trying to fetch) the element:
for (i; i < 9; i++) {
element = document.getElementById('h1-0' + i);
if (element) {
titles[i] = element.textContent;
}
else {
console.log("Element " + i + " not found.");
}
}
Then check the console to see which one is missing.

There are a couple ways you can fix this issue - you can test for a missing object and skip that case or you can catch the exception that is thrown and act accordingly in the exception handler.
Here's how you could handle missing objects in your code:
function generate(){
var titels = [];
var i, item, test;
for (i = 0; i < 9; i++) {
test = 'h1-0'+ i;
item = document.getElementById(test);
if (item) {
titels[i] = item.textContent;
}
}
document.getElementById("uitkomst").value = titels[1];
}
If, this is really all your code is doing, then you don't need the for loop because you're only using the [1] item from the array and you can do this:
function generate() {
var item = document.getElementById("h1-01");
if (item) {
document.getElementById("uitkomst").value = item.textContent;
}
}

Related

How to remove, order up, down elements in Javascript

I'm using JavaScript to remove, order up, order down a text row, it runs normally in IE, but not in Chrome or Firefox.
When I run, I received a message from console bug:
Uncaught TypeError: Failed to execute 'removeChild' on 'Node': parameter 1 is not of type 'Node'.
How to fix the error?
function dels(index) {
var frm = document.writeForm;
var opts = frm['ans' + index].value = ''; // eval("frm.ans_list" + index + ".options");
for (var i = 0; i < opts.length; i++) {
if (opts[i].selected) {
opts[i--].removeChild(true);
}
}
eval("frm.ans" + index + ".value = '' ");
setting_val(index);
}
function up_move(index) {
var frm = document.writeForm;
var opts = eval("frm.ans_list" + index + ".options"); // frm['ans' + index].value = '';
for (var i = 0; i < opts.length; i++) {
if (opts[i].selected && i > 0) {
tmp = opts[i].cloneNode(true);
opts[i].removeChild(true);
opts[i - 1].insertAdjacentElement("beforeBegin", tmp).selected = true;
}
}
setting_val(index);
}
**(UPDATED)**
function down_move(index)
{
var frm = document.writeForm;
var opts=frm["ans_list" + index].options // eval("frm.ans_list" + index + ".options"); // frm['ans' + index].value = '';
for (var i=opts.length-1; i>=0; i--) {
if (opts[i].selected && i<opts.length-1) {
tmp = opts[i].cloneNode(true);
opts[i].removeChild(true);
opts[i].insertAdjacentElement("afterEnd", tmp).selected = true;
}
}
setting_val(index);
}
<span class="bt_test_admin bg_type_01">Delete</span>
<span class="bt_test_admin bg_type_01">▲ Order</span>
<span class="bt_test_admin bg_type_01">▼ Order</span>
Wrong use of removeChild
if (opts[i].selected) {
opts[i--].removeChild(true);
}
The function is intended as:
ParentNode.removeChild(ChildNode);
// OR
ChildNode.parentNode.removeChild(ChildNode);
MDN Documentation on removeChild
Also, you can replace all your evals
eval("frm.ans" + index + ".value = '' ")
eval("frm.ans_list" + index + ".options")
It would be better written as
frm["ans" + index].value = ""
frm["ans_list" + index].options
Finally,
tmp = opts[i].cloneNode(true);
opts[i].removeChild(true);
opts[i].insertAdjacentElement("afterEnd", tmp).selected = true;
Cloning a node, appending the clone, and removing the original would be optimized as moving the original to its new location.
But, you try to remove the original, then insert the clone after the original. It's odd.
If I correctly understood what you try to do, this function could help you.
function reverse_options_order(select_element)
{
// we store the current value to restore it after reordering
const selected_value = select_element.value;
// document fragment will temporarily hold the children
const fragment = document.createDocumentFragment();
while (select_element.lastChild)
{
// last child become first child, effectively reversing the order
fragment.appendChild(select_element.lastChild);
}
// appending a fragment is equal to appending all its children
// the fragment will "merge" with the select_element seamlessly
select_element.appendChild(fragment);
select_element.value = selected_value;
}
You can use the same method to reverse any nodes order

'Uncaught TypeError: undefined is not a function' keeps showing up for different lines of code

I am trying to take a set of text, and when I hit a button have it change to a different set of text. I have been trying a lot of different methods, and cannot seem to get it to work. Here is a working Jsfiddle.
I keep getting 'Uncaught TypeError: undefined is not a function' for the line
var $rep = $update.textContent.substring(1);
I have changed this line of code, but will the get the same error on a different line of code within the same function.
function createAnswers() {
var i;
for (i = 0; i < 4; i++) {
var $update = $(".answers p")[i];
var $rep = $update.textContent.substring(1);
console.log($rep);
var answerText = document.createTextNode(randomImage.randomAnswers[i]);
if (usedImages.length >= 1) {
$rep.replaceWith(answerText);
}
$update.appendChild(answerText);
}
}
I am still pretty new at Javascript, so I may be missing something very obvious. Any constructive criticism will be helpful.
Your function should look like:
function createAnswers() {
var i,
$answers = $(".answers p");
for (i = 0; i < 4; i++) {
var $update = $answers[i];
var $rep = $update.textContent.substring(1);
var answerText = document.createTextNode(randomImage.randomAnswers[i]);
if (usedImages.length >= 1) {
$update.textContent = $update.textContent.replace($rep, answerText.textContent);
}
$update.appendChild(answerText);
}
}
You do not need to use jQuery functions after var $update = $(".answers p")[i];, because $update becomes an DOM node.
I figured it out. Thanks everybody for the help. I realized I needed to specify the use of text nodes, and updating the text node directly. Here is my final code:
function createAnswers() {
var i,
$update;
for (i = 0; i < 4; i++) {
$update = $(".answers p")[i];
console.log($update);
var answerText = document.createTextNode(randomImage.randomAnswers[i]);
if (usedImages.length === 0) {
$update.appendChild(answerText);
}
else {
$update.childNodes[1].nodeValue = randomImage.randomAnswers[i];
}
}
}

Why does the second loop execute before the first loop?

so this might be a repost, but I don't really know how to explain my second problem.
I have this code:
var paragraphsArray = new Array();
function setParagraphs(offSet)
{
offSet = offSet * 12;
for (var i = 1; i < 13; i++)
{
var parX = i + offSet;
var testASd = $.get('php/entryParagraphs.php', {idd: parX}).done(function(paragraph)
{
//clear paragraph1 div
document.getElementById("paragraph1").innerHTML = "";
//create p elements
var pElem = document.createElement("p");
pElem.setAttribute("id", "pEntry"+i);
document.getElementById("paragraph1").appendChild(pElem);
$("pEntry"+i).text(paragraph);
});
}
}
edited: I removed the second loop because it was unnecessary, for some reason the p element creation starts on i==13, which is the extra one that shouldn't even do.
for some reason the second loop executes first, so the paragraphArray is printed out as undefined. I managed to "fix" the order with the setTimeout() function, BUT I still get the undefined message, instead of the value. In the first loop the value is printed out fine, but if I try and put it in a $("p").text(paragraph); I also get undefined. So although I was right about the execution order, the problem is still there!
Because first is in ajax call, declare paragraphsArray in global space and use a callback function, try this:
*Updated
var paragraphsArray = [];
function setParagraphs(offSet) {
offSet = offSet * 12;
var request = 0;
for (var i = 1; i < 13; i++) {
var parX = i + offSet;
var testASd = $.get('php/entryParagraphs.php', {idd: parX}).done(function(paragraph) {
request++;
paragraphsArray[request] = paragraph;
console.log(paragraphsArray[request]);
if (request === 12) {
alert('first');
callback();
}
});
}
}
function callback() {
for (var i = 1; i < 13; i++) {
console.log(paragraphsArray[i]);
}
alert('second');
}
Run the second loop inside of the first loop.
function setParagraphs (offSet) {
//paragraphs
var testing = 0;
var paragraphsArray = new Array();
offSet = offSet * 12;
for (var i=1;i<13;i++) {
var parX = i + offSet;
var testASd = $.get('php/entryParagraphs.php', { idd: parX }).done(function(paragraph) {
paragraphsArray[i] = paragraph;
console.log(paragraphsArray[i]);
alert('first');
for (var i=1;i<13;i++) {
console.log(paragraphsArray[i]);
alert('second');
}
});
}
}
$.get is async function. 1st cycle will just send requests and wouldn't wait for response, so 2nd cycle will start right after first, without getting response of $.get function. Thats why console.log(paragraphsArray[i]); in 2nd cycle shows undefined.
You only can handle response in first cylce.
You can use $("p").text(paragraph); only like in this example:
var testASd = $.get('php/entryParagraphs.php', { idd: parX }).done(function(paragraph) {
paragraphsArray[i] = paragraph;
console.log(paragraphsArray[i]);
alert('first');
$("p").text(paragraph);
});
You can't use variables, which are assigned in function
function(paragraph) {
paragraphsArray[i] = paragraph;
console.log(paragraphsArray[i]);
alert('first');
$("p").text(paragraph);
}
outside of this function.
To achieve what you want you have to use another approach.
HTML will be:
<div id='paragraphs'>
</div>
JS code:
var testASd = $.get('php/entryParagraphs.php', { idd: parX }).done(function(paragraph) {
$("#results").append("<p>"+paragraph+"</p>")
});
You should use ~ this code. I just show you approach.

Google Apps Script: How to find a listItem object in a google document and insert a item to it?

Following the documentation sample, I'm trying to create a function that searchs for a numerated list in a google document and, if finds it, adds a new item to that list. But I get this error: Cannot find method setListId(string). (line 21, file "test") or, if I change line 21 content (replacing elementContentfor newElement), I get the message: Preparing for execution... and nothing happens. How to fix it?
This is my code:
function test() {
var elementContent = "New item testing"; // a paragraph with its formating
var targetDocId = "1R2c3vo9oOOjjlDR_n5L6Tf9yb-luzt4IxpHwwZoTeLE";
var targetDoc = DocumentApp.openById(targetDocId);
var body = targetDoc.getBody();
for (var i = 0; i < targetDoc.getNumChildren(); i++) {
var child = targetDoc.getChild(i);
if (child.getType() == DocumentApp.ElementType.LIST_ITEM){
var listId = child.getListId();
var newElement = body.appendListItem(elementContent);
newElement.setListId(newElement);
Logger.log("child = " + child);
}
}
}
Following my comment, I tried to play with your script to see what happened and I came up with that code below...
I'm not saying it solves your issue and/or is the best way to achieve what you want but at least it gives a result that works as expected.
Please consider it as a "new playground" and keep experimenting on it to make it better ;-)
function test() {
var elementContent = "New item testing"; // a paragraph with its formating
var targetDocId = DocumentApp.getActiveDocument().getId();
var targetDoc = DocumentApp.openById(targetDocId);
var body = targetDoc.getBody();
var childIndex = 0;
for (var i = 0; i < targetDoc.getNumChildren(); i++) {
var child = targetDoc.getChild(i);
if (child.getType() == DocumentApp.ElementType.LIST_ITEM){
while(child.getType() == DocumentApp.ElementType.LIST_ITEM){
child = targetDoc.getChild(i)
childIndex = body.getChildIndex(child);
Logger.log(childIndex)
i++
}
child = targetDoc.getChild(i-2)
var listId = child.getListId();
Logger.log(childIndex)
var newElement = child.getParent().insertListItem(childIndex, elementContent);
newElement.setListId(child);
break;
}
}
}

Javascript array results returning undefined

I have been working on a simple math game and am having problems getting the overall answer results to return after the end of the game.
Here is what my return function looks like
function pShowResults() {
var pNumResults = document.getElementById("results");
for (var i = 0; i <= 10; i++) {
pNumStore.push(pNumGuess[i]);
var pNumTable = document.createElement("div");
pNumTable.innerHTML = (pNumGuess[i]);
pNumResults.appendChild(pNumTable);
}
}
Here is the full script
Pretty much need debugging help. I new to this so I'm guessing there is a ton that's off, but as long as I can get the results fed back I should be fine.
You are not passing the value of x in many placess
$(document).ready(function () {
//declare arrays and variables for use below
var pNum1 = [];
var pNum2 = [];
var pNumAns = [];
var pNumGuess = [];
var pNumStore = [];
var pNumCarry = 0;
var pNumTrack = 0;
var pNumMessageRight = ['Awesome Job!', 'Correct!', 'Great Job!'];
var pNumMessageWrong = ['Oh No! That Was Wrong!', 'Incorrect!', 'That\'s Wrong'];
$(".Play").click(function () {
$("#popup").attr("class", "on");
pNumTrack = 0;
pNumGen(pNumTrack);
});
$(".pNumSubmit").click(function () {
pNumCalc(pNumTrack-1);
});
$(".pNumNext").click(function () {
pNumGen(pNumTrack);
});
function pNumGen(x) {
pNum1[x] = (Math.round(Math.random() * 51));
pNum2[x] = (Math.round(Math.random() * 51));
pNumAns[x] = pNum1[x] + pNum2[x];
$(".pNum1").html(pNum1[x]);
$(".pNum2").html(pNum2[x]);
$(".pNumGuess").val("");
$(".pNum1").html(pNumTrack[x]);
if (pNumTrack == 2) {
$(".pNumNext").html("");
$(".pNumSubmit").html("Close");
pShowResults();
}
pNumTrack++;
}
function pNumCalc(x) {
pNumGuess[x] = $(".pNumGuess").val();
if (pNumGuess[x] == pNumAns[x]) {
$(".message").html(pNumMessageRight[Math.floor(Math.random() * pNumMessageRight.length)]);
$(".pNumNext").html("Next Question >")
} else {
$(".message").html(pNumMessageWrong[Math.floor(Math.random() * pNumMessageWrong.length)]);
$(".pNumNext").html("Maybe The Next Question >")
}
}
function pShowResults() {
var pNumResults = document.getElementById("results");
for (var i = 0; i < pNumGuess.length; i++) {
pNumStore.push(pNumGuess[i]);
var pNumTable = document.createElement("div");
pNumTable.innerHTML = (pNumGuess[i]);
pNumResults.appendChild(pNumTable);
}
}
});
Demo: Fiddle
There is a function called pNumCalc in your code which you have set to take in an argument, but you never pass one in. You use the argument to store the results in the pNumGuess array, but since the argument is never passed in, the guesses are never stored, and you end up with undefined as the answers the user gave.
Updated fiddle: http://jsfiddle.net/dwdX9/2/. Not sure how close this is to what you actually want though, but hopefully it gets you on the right track.
Because StackOverflow wants code to to be included when JSFiddle is...:
pNumCalc(pNumTrack)
You forget to define array before use it.
function pShowResults() {
var pNumStore = new Array();
var pNumResults = document.getElementById("results");
for (var i = 0; i <= 10; i++) {
pNumStore.push(pNumGuess[i]);
var pNumTable = document.createElement("div");
pNumTable.innerHTML = (pNumGuess[i]);
pNumResults.appendChild(pNumTable);
}
}
I must suggest you should use jquery instead.
After visiting your Fiddle seems like there are many problems with the code. and also your question is unclear.
for e.g.
$(".pNumSubmit").click(function () {
//why x value not passed?
pNumCalc();
});
function pNumCalc(x) {
pNumGuess[x] = $(".pNumGuess").val();
if (pNumGuess[x] == pNumAns[x]) {
$(".message").html(pNumMessageRight[Math.floor(Math.random() * pNumMessageRight.length)]);
$(".pNumNext").html("Next Question >")
} else {
$(".message").html(pNumMessageWrong[Math.floor(Math.random() * pNumMessageWrong.length)]);
$(".pNumNext").html("Maybe The Next Question >")
}
}
Please clear which array is returning undefined so that others can help you.

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