Develop Reference

JavaScript: How Can I Make A Var "Array" Work?

Is there a way to name a var using a sort of "Array?" My code is this:
for(var i = 0; i < (getHorizontalSquares * getVerticalSquares); i++){
var Square[i] = document.createElement("div");
Square[i].style.position = "relative";
Square[i].style.float = "left";
Square[i].style.width = "50px";
Square[i].style.height = "50px";
Square[i].id = "square" + (i + 1);
for(var ii = 0; ii < 6; ii++){
var TestColor = TestColorArray[Math.round(Math.random()*(TestColorArray.length - 1))];
getTestColor += TestColor;
}
Square[i].style.backgroundColor = "#" + getTestColor;
SquareCont.appendChild(Square[i]);
}
I know my code doesn't work, but I want to implement the same idea so I can get a result of this:
var Square1...
var Square2...
var Square3...
var Square4...
var Square5...
etc
I also tried doing a "Concentration" var, but it didn't work. How do I do this so the document doesn't append the same square multiple times?

var Square = {};
var SquareCont = document.createElement('div');
var getHorizontalSquares = 10;
var getVerticalSquares = 10;
var TestColorArray = ['a','b','c','f','e','0','1','2','3','3','4','5'];
var getTestColor = '';
for(var i = 0; i < (getHorizontalSquares * getVerticalSquares); i++){
Square['Square'+i] = document.createElement("div");
Square['Square'+i].style.position = "relative";
Square['Square'+i].style.float = "left";
Square['Square'+i].style.width = "50px";
Square['Square'+i].style.height = "50px";
Square['Square'+i].id = "square" + (i + 1);
for(var ii = 0; ii < 6; ii++){
var TestColor = TestColorArray[Math.round(Math.random()*(TestColorArray.length - 1))];
getTestColor += TestColor;
}
Square['Square'+i].style.backgroundColor = "#" + getTestColor;
SquareCont.appendChild(Square['Square'+i]);
getTestColor = '';
}
console.log(Square);
This example does what you want using an object instead of an array, but meets your desire to dynamically create accessible Square1, Square2, etc... They are all contained in Square. In the console with this snippet, you will see that 100 squares are created and added to the Square object. They will be accessible by Square.SquareX (where X is some number), or Square['SquareX'], or Square['Square'+X] where X is some number again.

Your declaration syntax is not valid. But, I think the larger point you are trying to get to is to be able to populate an array with dynamically created elements and that you can do:
var squares = []; // Array must exist before you can populate it
var testColorArray = ["green", "yellow", "blue", "orange", "silver"];
var getTestColor = null;
function makeSquares(count){
for(var i = 0; i < count; i++){
// Just create the element and configure it. No need to worry about the array yet
var element = document.createElement("div");
element.style.float = "left";
element.style.width = "75px";
element.style.height = "75px";
element.id = "square" + (i + 1);
element.style.backgroundColor = testColorArray[Math.floor(Math.random()* testColorArray.length)];
element.textContent = element.id;
squareCont.appendChild(element);
// Now, add the element to the arrray
squares.push(element);
}
// Test:
console.log(squares);
}
makeSquares(10);
<div id="squareCont"></div>

How to generate random divs but not overlap

I want to generate random divs but not overlap with JavaScript.
Just like this:
random div example
But when the number of DIVS gets larger the browser will be blocked！
Then I use the Web Workers to generate the random divs,the browser will be blocked too.
here is my main js code:
self.onmessage = function(e){
var itemslength = e.data;
console.log(itemslength);
var position = [];
for(var i = 0 ; i < itemslength ; i++){
var length = position.length;
if(length == 0){
x = 900*Math.random();
y = 400*Math.random();
var relxy = [x,y];
position.push(relxy);
}else{
var flag = true;
x = 900*Math.random();
y = 400*Math.random();
do{
console.log('RUNNING!!');
x = x + 50;
y = y + 50;
var relxy = [x,y];
for(var j = 0 ; j < length ; j++){
var x1 = position[j][0];
var y1 = position[j][1];
var z = (x - x1)*(x - x1) + (y - y1)*(y - y1);
if(z > 10000){
flag = flag && true;
}else{
flag = flag && false;
}
}
}while(!flag);
position.push(relxy);
}
}
console.log('FINSHED!!');
postMessage(position);
};
<script>
var worker = new Worker('./js/bubbleworker.js');
var itemslengh = $('.items').length;
worker.postMessage(itemslengh);
worker.onmessage = function(data){
for(var i=0;i<data.data.length;i++){
var x = data.data[i][0];
var y = data.data[i][1];
$('.items:eq(' + i + ')').css({
'position':'absolute','left':x + 'px','top':y + 'px'
})
}
}
</script>
Am i right?
Someone who has a better idea? Thanks！

Make other nodes follow when dragging a node in Cytoscape.js

I'm new to cytoscape.js, I just want to make other nodes follow when dragging one node.
Appreciate your help

Write a listener, and update the other node positions appropriately in your callback:
eles.on()
node.position()

Here is how I did it. Note you have to save off the original positions at the grab event, and then update during the drag event.
function add_drag_listeners()
{
var all = cy.elements("node");
for (j = 0; j < all.length; j++)
{
cynode = all[j];
cynode.on("grab",handle_grab);
cynode.on("drag",handle_drag);
}
}
var grab_x = 0;
var grab_y = 0;
var drag_subgraph = [];
function handle_grab(evt)
{
grab_x = this.position().x ;
grab_y = this.position().y ;
var succ = this.successors();
drag_subgraph = [];
var succstr = "";
for (i = 0; i < succ.length; i++)
{
if (succ[i].isNode())
{
var old_x = succ[i].position().x;
var old_y = succ[i].position().y;
succstr += " " + succ[i].data("id");
drag_subgraph.push({old_x:old_x, old_y:old_y, obj:succ[i]});
}
}
}
function handle_drag(evt)
{
var new_x = this.position().x;
var new_y = this.position().y;
var delta_x = new_x - grab_x;
var delta_y = new_y - grab_y;
for (i = 0; i < drag_subgraph.length; i++)
{
var obj = drag_subgraph[i].obj;
var old_x = drag_subgraph[i].old_x;
var old_y = drag_subgraph[i].old_y;
var new_x = old_x + delta_x;
var new_y = old_y + delta_y;
obj.position({x:new_x, y:new_y});
}
}

Why can't I change the zIndex here?

I have a bunch of divs positioned on top of an image.
I am trying to make the fraction hidden by the div to appear on the mouse hover. To achieve this I tried setting the zIndex of the div to be lower than the one of the image so it gets revealed. But I can seem to select ALL the divs.
Here is my javascript code:
window.onload = function () {
var block = document.getElementById('container');
block.addEventListener('mouseover', function () {
var blocks = document.querySelectorAll("#container div");
var index = 0, length = blocks.length;
for (var index = 0; index < length; index++) {
blocks[index].style.zIndex = 2;
}
});
for (var i = 0; i < 40; i++) {
for (var j = 0; j < 40; j++) {
var div = document.createElement("div");
div.className = "block";
div.style.left = j * 25 + 'px';
div.style.top = i * 25 + 'px';
div.style.display = "inline-block";
div.style.verticalAlign = "top";
div.style.zIndex = "1";
document.getElementById("container").appendChild(div);
}
var jump = document.createElement("br");
document.getElementById("container").appendChild(jump);
}
};
Where did I go wrong? Thank you. The div container has the background image that is placed "under" the created inner divs.

document.querySelectorAll returns an array of elements. You would need to loop through them individually.
var blocks = document.querySelectorAll("#container div");
var index = 0, length = blocks.length;
for ( ; index < length; index++) {
blocks[index].style.zIndex = 1;
}
If you are only looking for a single element you can also use document.querySelector which returns the first element it finds that matches the selector and you can work directly on it as you originally had in your code.

how to create more elements for the entered value in a textboxes in javascript?

I use for loop to create 3 textboxes with it's ids in javascript.. if I enter numbers on each text box I want to display same number of paragraphs element under each text box..
I have a problem: each textbox affected when i enter value in the other text boxes..
There is my codes:
for (i = 0; i < 3; i++) {
var tx = document.createElement('input');
tx.setAttribute('id', i);
tx.onblur = function () {
for (i = 0; i < 3; i++) {
var no = document.getElementById(i).value;
num = Number(no);
var d = document.getElementById('di' + i);
for (x = 0; x < num; x++) {
var tx1 = document.createElement('p');
tx1.innerHTML = " p" + x;
d.appendChild(tx1);
}
}
};
var div1 = document.createElement('div');
div1.setAttribute('id', "di" + i);
var div = document.getElementById('div1');
div.appendChild(tx);
div.appendChild(div1);
}

There are issues in code.
1)
var div = document.getElementById('div1');
div.appendChild(tx);
The code is asking for div with ID div1 which is never appended to DOM hence it returns null
thus null.appendChild(tx) fails.
Thanks
Added JSFiddle. If this is what you are trying to make..
http://jsfiddle.net/khm63wte/

just change your code, create a div on your document <div id="t"></div>, in your javascript create div first, then your input and append them to the document here is a working code
for (i = 0; i < 3; i++) {
var div1 = document.createElement('div');
div1.setAttribute('id', "di" + i);
document.getElementById('t').appendChild(div1)
var tx = document.createElement('input');
tx.setAttribute('id', i);
document.getElementById("di"+i).appendChild(tx);
tx.onblur = function () {
for (i = 0; i < 3; i++) {
var no = document.getElementById(i).value;
num = Number(no);
var d = document.getElementById('di' + i);
for (x = 0; x < num; x++) {
var tx1 = document.createElement('p');
tx1.innerHTML = " p" + x;
d.appendChild(tx1);
}
}
};
}