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Adding Characters to the Begining of an Array that form words

When looking at set of characters I am trying to put each letter into a specifc order in an array. For Example: Given the Strings "cat" and "dog" I would want an array that contains [d,o,g,c,a,t], cat at the end of the array because it was read first.
Currently I have tried this:
However, when I try the code below assuming the strings are "cat" and "dog".
I get an array containing: [c,a,t,d,o,g]. Instead of push I have also tried .unshift but the array now reads: [g,o,d,t,a,c].
var chars = /^[a-z]$/;
var string = [];
function makeword(){
if(currentChar.match(chars)){
string.push(currentChar);
currentChar = getNextChar(); //Gets next Character in the String
makeword();
}
}
Is something like this possible in Javascript?

If I understood you correctly, you want to provide a list of strings, then have them show up in an array in reverse order, with each letter as an element of the array. The following function will do just that:
function makeWords() {
var arr = [];
for(var i = arguments.length - 1; i >=0; i--) {
arr.push(arguments[i]);
}
return arr.join('').split('');
}
so running makeWords('cat', 'dog') will result in ['d','o','g','c','a','t'].

It's a relatively simple code when a functional approach is used. The rest and spread operators are very handy both to collect the function arguments and to spread the characters of a word into an array.
var characterify = (...c) => c.reduceRight((a,b) => a.concat([...b]) ,[]);
document.write("<pre>" + JSON.stringify(characterify("cat","dog")) + "</pre>");

Allowing commas to follow through when converting array to string

I have an array of character with commas separating them. I need to split an array but retain my comma inbetween each character.
See below for an example array:
var myArray = [a,,,b,c,d,,,]
There's a comma in there between the characters "a" and "b". I need to retain the comma when converting the array to a string.
The output string needs to resemble this:
a,bcd,
This is what i'm currently doing to retain the commas:
myArray.toString().replace(/,/g, "");

The Array's toString() method basically does a join(",") which is why you are getting the extra commas in your string.
Instead use join("") if you want to join the elements without the delimiter being added as part of the string
var myArray = ["a",",","b","c","d",",",]
document.body.innerText = myArray.join("");

How about you use :
var myArray = [a,,,b,c,d,,,];
var str = myArray.join();
This will give a string of array elements, preserving the commas.

if you want it to maintain the centre comma you should create your array as
var myArray = [a,",",b,c,d,",",];
this will then treat the middle comma in the set of 3 as a string containing that character rather than the array seperator

You could change your regex, to replace item,item for item item.
myArray.toString().replace(/([a-z,]),([a-z,])/g, "$1$2")

Basically you have a sparse array and want to extract only filled values and convert it to string ? Here is one, probably not the best, solution :
var myArray = ['a',',',',','b',',','c']
var resultArray = [];
for(var i = 0; i < myArray.length; i++){
if(myArray[i] !== ','){// allow 0, false, null values, but not undefined
resultArray.push(myArray[i]);
}
}
console.log(resultArray);
Working plnkr : http://plnkr.co/edit/55T6PGI9DuTlvy6k88hr?p=preview, check the console of your broswer.

If this is an actual array of strings and you wanted only those with actual values, you could use the filter() function to filter out any non-undefined ones :
// Your example array
var input = ['a',,,'b','c','d',,,];
// Remove any undefined elements
var output = input.filter(function(e){ return e; }); // yields ['a','b','c','d']
You could then use the join() function to create a string with your elements :
var result = output.join(); // yields "a,b,c,d"
Example Snippet
var input = ['a',,,'b','c','d',,,];
document.write('INPUT: ' + input + '<br />');
var output = input.filter(function(e){ return e; });
document.write('OUTPUT: ' + output);

Arrays and strings in javascripts

Array1 = ['1,2,3']
How can I retrieve the numerical values by transforming it into non-string?
I've been trying parseInt, but I can only manage to get 1 as end-result.
Thanks.

If you start with an array containing a string, like in your example, you need to use split().
Example:
Array1 = ['1,2,3'];
var new_array = Array1[0].split(','); // new_array is ["1", "2", "3"]
for (var i = 0; i < new_array.length; i++) {
new_array[i] = parseInt(new_array[i]);
}
// new_array is now [1, 2, 3]

I would re-look why you're storing a comma separated string as an array element; but, if the reasoning is valid for your particular design, the question is do you have an array with more than one comma-separated string like this?
If you can, re-work your design to actually use an array of integers, so use:
var arr = [1,2,3];
instead of ['1,2,3'].
If you are storing comma separated strings as array elements, you can get each index as an array of integers using something like the following:
var array1 = ['1,2,3', '4,5,6,7'];
function as_int_array(list, index) {
return list[index].split(',').map(function(o) { return parseInt(o,10); });
}
console.log("2nd element: %o", as_int_array(array1, 1));
// => 2nd element: [4,5,6,7]
Hope that helps.

Generally parseInt() takes anything(most of the time string) as input and returns integer out of that input. If it doesn't get any integer then it returns NaN.
Why you are getting 1 !!!
Whenever you are using parseInt() it tries to read your input character by character. So according to your input
var Array1 = ['1,2,3'];
first it get's '1' and after that ',' (a comma, which is not a number) so it converts '1' into Integer and returns it as your result.
Solution of your problem :
var Array1 = ['1,2,3'];
//just displayed the first element of the array, use for or foreach to loop through all the elements of the array
alert(Array1[0].split(',')[0]);

Remove all elements from array of strings that do not contain "IN"

I need to remove all elements in an array that do not contain "IN" in uppercase exactly like that.
How I thought of doing this was to traverse the array with a for loop and write all values that contain IN to another array.
Is there a way I can do it without writing to a new array and just removing those items that don't match from the current array?
Here is the code for how I was planning on doing it:
arrTwo = [];
for(var i = 0; i<arr.length; i++){
if(arr[i].indexOf('IN') > -1) arrTwo.push[arr[i]];
}

You can use ES5 filter method:
arr = arr.filter(function(s){
return ~s.indexOf("IN");
});
And using ES6 arrow functions, it can be simplified to:
arr = arr.filter(s=>~s.indexOf("IN"));

Here's a really good thread that has a couple of ways to accomplish this. If you do not delete the element of the array in the correct manner, you that element will be undefined rather than actually deleted. The .spilce() method is what you want to look into.
Deleting array elements in JavaScript - delete vs splice

I would do it using the splice() method:
var testArray = [ 'this one contains IN', 'this one does not' ];
function filterArray ( arr ) {
var i = arr.length;
//-- Loop through the array in reverse order since we are modifying the array.
while (i--) {
if (arr[i].indexOf('IN') < 0) {
//-- splice will remove the non-matching element
arr.splice(i, 1);
}
}
}
filterArray( testArray );
document.body.innerText = JSON.stringify(testArray);
JSFiddle: http://jsfiddle.net/5DW8L/1/

Javascript check every char in a string and return array element on corresponding position

Got a string that is a series of 0 or 1 bit and an array of values, if in the string are characters that are set to 1, I need to return the corresponding value from the array.
example: mystring = "0101"; myarray =["A","B","C","D"]; then result = "B,D"
how can I get this result?
for(var i=0;i<mystring.length;i++){
if(mystring[i] != 0)
{
result = myarray[i];
}
}

Your code seems to work just fine, so you can just add another array and push the values on to that:
var result = [];
for (var i = 0 ...
result.push(myarray[i]);
http://jsfiddle.net/ExplosionPIlls/syA2c/
A more clever way to do this would be to apply a filter to myarray that checks the corresponding mystring index.
myarray.filter(function (_, idx) {
return +mystring[idx];
})
http://jsfiddle.net/ExplosionPIlls/syA2c/1/

Iterate through the characters in the binary string, if you encounter a 1, add the value at the corresponding index in the array to a temporary array. Join the temporary array by commas to get the output string.

I am not really sure if this is what you are looking for, but this returns the array of matches.
var result = [];
for(var i=0;i<mystring.length;i++){
if(parseInt(mystring[i]) !== 0 ) {
result.push(myarray[i]);
}
}
return result;

result = new Array();
for(var i=0;i