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Array functions 'push' and 'splice' Javascript

1 of spades,1 of diamonds,1 of clubs,1 of hearts,2 of spades,2 of diamonds,2 of clubs,2 of hearts,3 of spades,3 of diamonds,3 of clubs,3 of hearts,4 of spades,4 of diamonds,4 of clubs,4 of hearts,5 of spades,5 of diamonds,5 of clubs,5 of hearts,6 of spades,6 of diamonds,6 of clubs,6 of hearts,7 of spades,7 of diamonds,7 of clubs,7 of hearts,8 of spades,8 of diamonds,8 of clubs,8 of hearts,9 of spades,9 of diamonds,9 of clubs,9 of hearts,10 of spades,10 of diamonds,10 of clubs,10 of hearts
,,,
[This is what the program returns]
I'm trying to make a program in JavaScript that allows someone to play poker. I am using the ProcessingJS terminal in Khan Academy. Below is my full program so far. What it's supposed to do is make an array called deck which includes the names of all the cards (not including the face cards) in a deck of cards. That part of the program works. The next part attempts to make a new array called current that is an exact copy of deck. It then tries to print out current, and it does so successfully.
The last for loop is what is causing the problem. It tries to take a random card from current and copy it to another array called player which is supposed to be the player's hand. It then tries to remove that card from the array current.
However, when it tries to print out the array player, all it prints is three commas. I have no idea what the issue is and I have looked at many websites that talk about push and splice. I really have no idea what is wrong.
Again, I want the program to display the player's hand. Thank you for your help.
var deck = [];
var current = [];
var enemy = [];
var player = [];
var suits = ['spades', 'diamonds', 'clubs', 'hearts'];
for (var i = 1; i < 11; i++) {
for (var x = 0; x < 4; x++) {
if (i <= 10) {
deck.push(i + ' of ' + suits[x]);
}
}
}
for (var c = 0; c < 40; c++) {
current[c] = deck[c];
}
println(current);
var y;
for (var a = 0; a < 4; a++) {
y = random(0, (current.length - 1));
player.push(current[y]);
current.splice(y);
}
println(player);

Why not just simplify this without using splice?
From what I understand, you're drawing the card using random. So, just push that card to the players hand with player.push(current[y]).
Also, when you call current.splice(y), I don't think you're deleting just the card that was drawn. That deletes every card in the deck after the index y. Change this to current.splice(y, 1).

Angular material pagination next page function

I follow this tutorial to learn how to make a pagination.
https://github.com/feichao/angular-material-paging
I put a json, myData, with items to see how will work. Because I'm a junior programmer eI got blocked to gotoPage().
In my page I changed:
ctrl.total = ctrl.myData.length;
ctrl.currentPage = 1;
ctrl.step = 6;
ctrl.gotoPage = function() {
if(ctrl.total) {
for(var i=0; i < ctrl.total; i++) {
//
}
}
};
but I don't know what to put in this function to show me only, let say 10 items, from my json, per page.
You can see these props and methods in their demo.
Can someone please give ideas how to do this?

You need to calculate the starting amount and then iterate until you hit the max for that page
ctrl.total = ctrl.myData.length; //the total items in your set
ctrl.currentPage = 1;
ctrl.step = 6; //page size? this could be 10 if you want
ctrl.numpages = ctrl.total/ctrl.step; //the total number of items partitioned by page size. convert this to a whole number (the ceiling)
//go to page function here receives the indexes for that page, is that ok?
ctrl.gotoPage = function(Page) { //i modified this to take the page number as an argument
if(Page<= ctrl.numpages && Page>0) //we need to check that the page is valid
{
var startpos = ((Page-1)*(ctrl.step))+1; //this is virtually a skip amount. If its the first page, i = 0, otherwise we start with an increment of the page size. If its the second page, we skip the first 6 results
for(var i=startpos; i < startpos+ctrl.step; i++) {
if(i == ctrl.total) //if its the last page we cut it off early
break;
}
}
};

Google apps script - Broken for loop

I'm working in Google apps script and seem to have screwed up one of my for loops. I'm sure that I am missing something trivial here, but I can't seem to spot it.
Code Snippet:
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheets = ss.getSheets();
var lastRow = sheets[3].getLastRow();
var zw = sheets[3].getRange(2, 1, lastRow - 1, 26).getValues();
for (var j = 0; j < zw.length; ++j) {
if (zw[j][9] === 'Yes') {
var masterEmail = [];
var firstLetterLastName = [];
var first2Letter = [];
var masterEmail.push(zw[j][22]);
var firstLetterLastName.push(zw[j][1].charAt(0).toLowerCase());
var first2Letter.push(zw[j][1].charAt(0).toLowerCase() + zw[j][1].charAt(1).toLowerCase());
//The rest of the function follows...
}
}
What's Not Working:
The for loop doesn't increment. When running the code in a debugger, var j stays at a value of 0.0, and the rest of the function only runs based of off the values in the 0 position of zw.
What I need it to do (AKA - How I thought I had written it:)
The ZW variable is holding a 2 dimensional array of cell values from a Google sheet. I'm looping through that, checking the 9th value of each array entry for a string of "Yes" and then running the rest of the function (for each column with a "Yes") if the condition is true.
I thought I had this working before, but recently had to restructure and optimize some things. Now I'm starting to think I may need to rethink things and use a different loop method. Can anyone educate me?
Edit: Here's a bit more context as requested:
function menuItem1() {
var ui = SpreadsheetApp.getUi();
var response = ui.alert('Are you sure you want to send emails?', ui.ButtonSet.YES_NO);
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheets = ss.getSheets();
var lastRow = sheets[3].getLastRow();
var zw = sheets[3].getRange(2, 1, lastRow - 1, 26).getValues();
if (response === ui.Button.YES) {
for (var j = 0; j < zw.length; j++) {
if (zw[j][9] === 'Yes') {
var firstLetterLastName = [];
firstLetterLastName.push(zw[j][1].charAt(0).toLowerCase());
//Other Stuff....
}
}
}
}
I have a menu item attached to a simple onOpen, that calls menuItem1(). Calling the function prompts the user with a warning that they are about to send emails, then goes about getting data to assign email addresses based on the contents of the sheets. firstLetterLastName is an example.
I'm still not getting the loop to function, is it because I have it between two if statements? (Here is a link to the sheet)

Indeed it is quite trivial. You have mixed up your increment. You wrote
for (var j = 0; j < zw.length; ++j)
which means that you do 1 + i (and we know that at the start i = 0 which means your value will always be 1) instead of using the usual
for (var j = 0; j < zw.length; j++)
which would mean that you do i + 1 and update i, so you will get the expected 0 + 1 1 + 1 etc
EDIT:
First, I recommend instead of something like
if (responseMir === ui.Button.YES) {
// Your For loop
doing
if (responseMir !== ui.Button.YES) {
return
}
and in a similar fashion in the for loop
if (zw[j][9] !== 'Yes') {
break
}
It mostly helps increase readability by not including large blocks of code under a single if, when all you want to do is to stop execution.
Your for loop gets broken because of the mistake here:
teacherEmailMir.push(selValsMir[j][7]);
So your loop will go over once. However on the next itteration, you try to push selValsMir[1][7] which does not exist. Note that each itteration you have var selValsMir = []; inside the loop, which means that for every j selValsMir will always be an empty array. So with the following line
selValsMir.push([zw[j][0], zw[j][1], zw[j][2], zw[j][3], zw[j][4], zw[j][5], zw[j][7], zw[j][22], zw[j][23], zw[j][24]]);
your array will always have selValsMir.lenght = 1 and selValsMir[0].length = 10. So obviously trying to access anything from selValsMir[1] will throw you an error and stop the script right there.
I also recommend looking over the if statements that look at the first and first 2 letters of the name as I believe you can accomplish the same with less code. Always try to streamline. Consider using switch() where you end up using a lot of else if

Variable Becomes Undefined in Last Iteration of Loop

I have a application where I am getting route info from one location to another, possibly between multiple locations. In my function, I'm looping over checked locations and writing out the directions to the page with jQuery. On the last iteration of the loop the 'myRoute' variable becomes undefined. So, if I have three locations, it bombs on the third, but if I use those same three and add a fourth, the first three works and the fourth bombs. I traced the behavior in Firebug, and while the myRoute variable does get filled properly, as soon as it moves to the next line, it is all of a sudden undefined. I removed instances of myRoute and replaced with directionResult.routes[0].legs[i] but still got the undefined error. What's going on here?
function setInstructions(directionResult, idname, start) {
//clean tour list
$('#tours_list .tour').remove();
$('#routeTitle').show();
var checkboxArray = $(".selector.Favs" + idname).find("li");
var idx = 0;
var linkMap = $('#routeTitle').find('.link-map')[0];
linkMap.href = __mapLink+'saddr=' + start;
var firstStop = true;
//iterate selected properties
for (var i = 0; i < checkboxArray.length; i++) {
var curChk = checkboxArray[i];
if ($(curChk).hasClass('active')) {
//get steps
var myRoute = directionResult.routes[0].legs[i]; //this is what becomes undfined
var title = $('<div>').addClass('mileage').append($('<p>').append($('<strong>').html(myRoute.distance.text + "<br /> about " + myRoute.duration.text)));
var ol = $('<ol>').addClass('directions');
for (var j = 0; j < myRoute.steps.length; j++) {
var step = myRoute.steps[j];
var li = $('<li>').append($('<div>').addClass('direction').html(step.instructions));
li.append($('<div>').addClass('distance').html(step.distance.text + " - " + step.duration.text));
ol.append(li);
}
//add tour with directions
$('#tours_list').append(temp);
}
}
}

The issue is that the array in directionResult.routes[0].legs is not as long as checkboxArray.length so your code is trying to access beyond the end of directionResult.routes[0].legs and thus gets undefined.
It isn't helping you that you are testing for only active class items because i goes from 0 to checkboxArray.length - 1 regardless.
I don't follow exactly what you're trying to do, but you might be able to work around this by only iterating the items that have .active in the first place so i never goes beyond the number of active items. You might be able to do that by changing this:
var checkboxArray = $(".selector.Favs" + idname).find("li");
to this:
var checkboxArray = $(".selector.Favs" + idname).find("li.active");
And, then remove the if check for the active class. This will make it so your index i never goes higher than the number of active items.
You could also just keep a counter of the active items you've processed and use that counter to index into directionResult.routes[0].legs[cntr] instead of using i.

Generating random unique data takes too long and eats 100% CPU

WARNING: CPU Usage goes to 100%, be careful.
Link to the jsFiddle
This script has been written to design a dynamic snake and ladder board. Everytime the page is refreshed a new board is created. Most of the time all of the background images do not appear, and the CPU usage goes up to 100%. But on occasion all of them appear and the CPU usage is normal.
Opera shows some of the background images, Firefox lags and asks me if I wish to stop the script.
I believe that the problem is with these lines of code:
for(var key in origin) // Need to implement check to ensure that two keys do not have the same VALUES!
{
if(origin[key] == random_1 || origin[key] == random_2 || key == random_2) // End points cannot be the same AND starting and end points cannot be the same.
{
valFlag = 1;
}
console.log(key);
}

Your algorithm is very ineffective. When array is almost filled up, you literally do millions of useless iterations until you're in luck and RNG accidentally picks missing number. Rewrite it to:
Generate an array of all possible numbers - from 1 to 99.
When you need a random numbers, generate a random index in current bounds of this array, splice element and this random position, removing it from array and use its value as your desired random number.
If generated numbers don't fit some of your conditions (minDiff?) return them back to array. Do note, that you can still stall in loop forever if everything that is left in array is unable to fit your conditions.
Every value you pull from array in this way is guaranteed to be unique, since you originally filled it with unique numbers and remove them on use.
I've stripped drawing and placed generated numbers into array that you can check in console. Put your drawing back and it should work - numbers are generated instantly now:
var snakes = ['./Images/Snakes/snake1.png','./Images/Snakes/snake2.jpg','./Images/Snakes/snake3.gif','./Images/Snakes/snake4.gif','./Images/Snakes/snake5.gif','./Images/Snakes/snake6.jpg'];
var ladders = ['./Images/Ladders/ladder1.jpg','./Images/Ladders/ladder2.jpg','./Images/Ladders/ladder3.png','./Images/Ladders/ladder4.jpg','./Images/Ladders/ladder5.png'];
function drawTable()
{
// Now generating snakes.
generateRand(snakes,0);
generateRand(ladders,1);
}
var uniqNumbers = []
for(var idx = 1; idx < 100; idx++){ uniqNumbers.push(idx) }
var results = []
function generateRand(arr,flag)
{
var valFlag = 0;
var minDiff = 8; // Minimum difference between start of snake/ladder to its end.
var temp;
for(var i = 0; i< arr.length; ++i) {
var valid = false
// This is the single place it still can hang, through with current size of arrays it is highly unlikely
do {
var random_1 = uniqNumbers.splice(Math.random() * uniqNumbers.length, 1)[0]
var random_2 = uniqNumbers.splice(Math.random() * uniqNumbers.length, 1)[0]
if (Math.abs(random_1 - random_2) < minDiff) {
// return numbers
uniqNumbers.push(random_1)
uniqNumbers.push(random_2)
} else {
valid = true
}
} while (!valid);
if(flag == 0) // Snake
{
if(random_1 < random_2) // Swapping them if the first number is smaller than the second number.
{
var temp = random_1; random_1 = random_2; random_2 = temp
}
}
else // Ladders
{
if(random_1>random_2) // Swapping them if the first number is greater than the second number.
{
var temp = random_1; random_1 = random_2; random_2 = temp
}
}
// Just for debug - look results up on console
results.push([random_1, random_2])
}
}
drawTable()

I had a problem like this using "HighCharts", in a for loop - "browsers" have an in-built functionality to detect dead scripts or infinite loops. So the browsers halts or pop-ups up a message saying not responding. Not sure if you have that symptom!
This was resulted from a "loop" with a large pool of data. I wrote a tutorial on it on CodeProject, you might try it, and it might be your answer.
http://www.codeproject.com/Tips/406739/Preventing-Stop-running-this-script-in-Browsers