Develop Reference

How to iterate a JavaScript code for two objects

I would like to apply same piece of code to two objects in JavaScript.
When calling getElementsByClass ,there appears 2 objects in my website.So I would like to apply the same code for both of them.Currently I'm applying it to only one Object (text[0]) and I would like to implement it also to text[1] .
var text=document.getElementsByClassName("th");
var text =text[0];
var newDom = '';
var animationDelay = 6;
for(let i = 0; i < text.innerText.length; i++)
{
newDom += '<span class="char">' + (text.innerText[i] == ' ' ? ' ' : text.innerText[i])+ '</span>';
}
text.innerHTML = newDom;
var length = text.children.length;
for(let i = 0; i < length; i++)
{
text.children[i].style['animation-delay'] = animationDelay * i + 'ms';
}
}

I think you want to do the same thing with using item[0] and item[1] together.
You can create a function. Or call this function by iterating your items too.
var text=document.getElementsByClassName("th");
function myFunc(text) {
var newDom = '';
var animationDelay = 6;
for(let i = 0; i < text.innerText.length; i++)
{
newDom += '<span class="char">' + (text.innerText[i] == ' ' ? ' ' : text.innerText[i])+ '</span>';
}
text.innerHTML = newDom;
var length = text.children.length;
for(let i = 0; i < length; i++)
{
text.children[i].style['animation-delay'] = animationDelay * i + 'ms';
}
}
}
myFunc(text[0]); // call functions with your items.
myFunc(text[1]);

Displaying times table using javascript

As I am new to JavaScript, I am a bit confused of using the for loops in JavaScript. I have tried the times table using the below JavaScript code, but I was unsuccessful in creating the times table for 1 to 9, as displayed in the image.
var display = ""; // The table output HTML
for (i = 1; i <= 9; i++) {
var multiplier = 1;
var result = i * 1;
display += multiplier + " * " + i + " = " + result + "\xa0\xa0\xa0\xa0\xa0\xa0\xa0 " ;
}
document.getElementById("outputDiv").innerHTML = display;
I tried using nested for loops, but it left me with an error
This is where I have done with a single for loop
https://codepen.io/vbudithi/pen/LgEPwx
I tried to get the output in the below form
THANKS IN ADVANCE

Use nested loop with break line. "< br >"
Working example: https://codepen.io/anon/pen/yRyLje
var display = "";
for( i = 1; i < 10; i++){
for (j = i; j < 10; j++) {
display += i + " * " + j + " = " + j * i+ "\xa0\xa0\xa0\xa0\xa0" ;
}
display +="<br>";
}
document.getElementById("outputDiv").innerHTML = display;

just like NicolasB said, wrapping the loop in another loop
var display = ""; // The table output HTML
for(j = 1; j <= 9; j++) {
for (i = j; i <= 9; i++) {
var result = i * j;
display += j + " * " + i + " = " + result + "\xa0\xa0\xa0\xa0\xa0\xa0\xa0 " ;
}
display += "<br>";
}
document.getElementById("outputDiv").innerHTML = display;

JavaScript: Cannot read property 'value' of null from textbox

function create(param) {
var i, target = document.getElementById('results');
target.innerHTML = '';
for(i = 1; i <= param; i += 1) {
target.innerHTML +='<br>'
for(var j=1;j<=param;j+=1)
target.innerHTML += '<input type="text" id="a'+i+''+j+'" placeholder="a'+i+''+j+'">';
}
}
function saveData(param) {
var a = []
for(var i = 1;i<param;i+=1) {
a[i] = [];
for(var j = 1;j<param;j+=1)
a[i][j] = document.getElementById('"a'+i+''+j+'"').value;
}
var target = document.getElementById('ShowResults');
for(var i = 1;i<param;i+=1){
a[i] = [];
target.innerHTML +='<br>'
for(var j = 1;j<param;j+=1)
target.innerHTML +=a[i][j];
}
}
<button onclick="create(5)" style="widht:300px;height:30px;">Create table</button>
<div id="results"> </div>
<button id="takeResults" onclick="saveData(5)"style="widht:300px;height:30px;">Save data</button>
<div id="ShowResults"> </div>
Ok so i made a table whit js and gave every textbox id of "a'+i+''+j+'" but it seems that when i want to save the data it show's me the following error: Cannot read property 'value' of null
Can you guys tell me what i did wrong?

Here's the solution with some code improvements
As i said in the comment, you had a mistake in the code you getElementById('"a' + i + '' + j + '"') should be getElementById('a' + i + '' + j)
and there's a lot of unnecessary loops
function create(param) {
var target = document.getElementById('results');
target.innerHTML = '';
for (var i = 0; i < param; i++) {
target.innerHTML += '<br>'
for (var j = 0; j < param; j++)
target.innerHTML += '<input type="text" id="a' + i + '' + j + '" placeholder="a' + i + '' + j + '">';
}
}
function saveData(param) {
var target = document.getElementById('ShowResults');
target.innerHTML = '';
var a = []
for (var i = 0; i < param; i++) {
a[i] = [];
for (var j = 0; j < param; j++) {
target.innerHTML += document.getElementById('a' + i + '' + j).value;
}
target.innerHTML += '<br>'
}
}
<button onclick="create(5)" style="widht:300px;height:30px;">Create table</button>
<div id="results"> </div>
<button id="takeResults" onclick="saveData(5)" style="widht:300px;height:30px;">Save data</button>
<div id="ShowResults"> </div>

Change this...
a[i][j] = document.getElementById('"a'+i+''+j+'"').value;
to this...
a[i][j] = document.getElementById('a' + i + j).value;
You have two lots of quotes around the id when you create it, but you don't need to add them both when you're using getElementById. Just build the string and it will work.
There were some other issues with your code, mainly where you didn't have opening braces but you had closing braces. Copy/paste this and it should fix your issues...
function create(param) {
var i, target = document.getElementById('results');
target.innerHTML = '';
for(i = 1; i <= param; i += 1) {
target.innerHTML +='<br>'
for(var j=1;j<=param;j+=1) {
target.innerHTML += '<input type="text" id="a'+i+''+j+'" placeholder="a'+i+''+j+'">';
}
}
function saveData(param) {
var a = []
for(var i = 1;i<param;i+=1) {
a[i] = [];
for(var j = 1;j<param;j+=1) {
a[i][j] = document.getElementById('a' + i + j).value;
}
var target = document.getElementById('ShowResults');
for(var i = 1;i<param;i+=1) {
a[i] = [];
target.innerHTML +='<br>'
for(var j = 1;j<param;j+=1) {
target.innerHTML +=a[i][j];
}
}
}
}
Incidentally, using multiple layers of arrays can cause issues, mainly due to being unfriendly for the reader (or you in the future). I'd highly recommend using an array of objects instead, and naming things more appropriately than a, i & j.

How to implement this Javascript to Blogger?

Please help, I can't implement this javascript to my Blogger...
(function() {
var pre = document.getElementsByTagName('pre'),
pl = pre.length;
for (var i = 0; i < pl; i++) {
pre[i].innerHTML = '<span class="line-number"></span>' + pre[i].innerHTML + '<span class="cl"></span>';
var num = pre[i].innerHTML.split(/\n/).length;
for (var j = 0; j < num; j++) {
var line_num = pre[i].getElementsByTagName('span')[0];
line_num.innerHTML += '<span>' + (j + 1) + '</span>';
}
}
})();
You can see this Javascript work fine here : http://jsfiddle.net/tovic/AbpRD/1/

If you are seeing that following type of error when you try to add this JavaScript snippet in your theme code -
Error parsing XML: The content of elements must consist of well-formed character data or markup.
Then to resolve this error, use any of the following methods -
1. Wrap the code within a CDATA directive in the script tag. The code will look like -
<script>
//<![CDATA[
(function() {
var pre = document.getElementsByTagName('pre'),
pl = pre.length;
for (var i = 0; i < pl; i++) {
pre[i].innerHTML = '<span class="line-number"></span>' + pre[i].innerHTML + '<span class="cl"></span>';
var num = pre[i].innerHTML.split(/\n/).length;
for (var j = 0; j < num; j++) {
var line_num = pre[i].getElementsByTagName('span')[0];
line_num.innerHTML += '<span>' + (j + 1) + '</span>';
}
}
})();
//]]>
</script>
The only downside of this approach being that Blogger XML parser will ignore any data layout tags (like for example <data:blog.homepageUrl/>) within the CDATA directive. Rather than replacing them with their actual values, it will not interpret them and show them as is.
2. Escape the following characters in your code -
" is replaced with "
& is replaced with &
< is replaced with <
> is replaced with >
After escaping, the code should look like -
<script>
(function() {
var pre = document.getElementsByTagName('pre'),
pl = pre.length;
for (var i = 0; i & lt; pl; i++) {
pre[i].innerHTML = '<span class="line-number"></span>' + pre[i].innerHTML + '<span class="cl"></span>';
var num = pre[i].innerHTML.split(/\n/).length;
for (var j = 0; j & lt; num; j++) {
var line_num = pre[i].getElementsByTagName('span')[0];
line_num.innerHTML += '<span>' + (j + 1) + '</span>';
}
}
})();
</script>
The data layout tags will remain functional when following this method. Remember to not escape <> surrounding the data layout tag (aka <data:blog.homepageUrl/> will work but not <data:blog.homepageUrl/>)
3. If no data layout tags have to be included in the JavaScript. Then you can add it in an HTML/JavaScript gadget via the Layout tab instead of directly including it in the theme code.

javascript printing to previous line

I have a bit of code that requires printing underscores but to the line above it, how would i do this? I'm not sure how to print the underscore to the previous line, not much experience with javascript. thanks!
var landscape = function() {
var result = "";
var flat = function(size) {
for (var count = 0; count < size; count++)
result += "_";
};
var hill = function(size) {
result += " /";
for (var count = 0; count < size; count++)
result += ""+
"_";
result += " \\";
};
//BUILD SCRIPT
flat(3)
hill(4);
flat(6);
hill(1);
flat(1);
//END SCRIPT
return result;
it makes this ___ /____ \______ /_ \_`enter code here`enter code here`
and i want this
_____ ___
___/ \__/ \____/\_

You can keep track of the two lines separately and then concatenate them just before returning the result.
JS:
function landscape() {
var resultTop = '';
var resultBottom = '';
function hill(size) {
resultTop += ' ';
resultBottom += '/';
for (var i = 0; i < size; i++) {
resultTop += '_';
resultBottom += ' ';
}
resultTop += ' ';
resultBottom += '\\';
}
function flat(size) {
for (var i = 0; i < size; i++) {
resultTop += ' ';
resultBottom += '_';
}
}
flat(3);
hill(4);
flat(6);
hill(1);
flat(1);
var result = resultTop + '<br/>' + resultBottom;
return result;
}
Here's a fiddle.

One workaround is to print a unicode character that draws a line on top. Turns out there is such a character: the Upper One-eighth Block
It's "\u2594" in unicode escape or ▔ as HTML entity or you can simply copy/paste the literal character from the example below:
____/▔▔▔▔\____/▔▔\___