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why my code doesn't work when I am trying to concatenate a function's return value with a string?

So, in this code I have a string of 0's and 1's and the length of the string is 32, which will be split in 6 equal parts but the last part will have the length of 2 so I will add (4) 0's after that which will make its length 6. So I wrote a function that will add the remaining 0's which is padding(num).
And that function will be invoked in side the slicing(str) function.
But the code breaks when I try to do execute.
Any help?
Thanks.
// This code works.
function padding0s(num) {
let s = "";
for (i = 0; i < 6 - num; i++) {
s += "0";
}
return s;
}
function slicing(str) {
let k = 6;
let res = [];
let temp1 = 0;
let f = padding0s(2);
for (i = 0; i < str.length; ) {
res.push(str.slice(i, k));
i += 6;
k += 6;
if (res[temp1].length !== 6) {
res[temp1] += f;
}
temp1++;
}
console.log(res);
}
slicing("01000011010011110100010001000101");
// But this does not..
function padding0s(num) {
let s = "";
for (i = 0; i < 6 - num; i++) {
s += "0";
}
return s;
}
function slicing(str) {
let k = 6;
let res = [];
let temp1 = 0;
for (i = 0; i < str.length; ) {
res.push(str.slice(i, k));
i += 6;
k += 6;
if (res[temp1].length !== 6) {
let f = padding0s(res[temp1].length);
res[temp1] += f;
}
temp1++;
}
console.log(res);
}
slicing("01000011010011110100010001000101");

Always define variables before using them
Not doing so can result in undefined behaviour, which is exactly what is happening in your second case. Here is how:
for (i = 0; i < str.length; ) {...}
// ^ Assignment to undefined variable i
In the above for-loop, by using i before you define it, you are declaring it as a global variable. But so far, so good, as it doesn't matter, if not for this second problem. The real problem is the call to padding0s() in your loop. Let's look at padding0s:
function padding0s(num) {
...
for (i = 0; i < 6 - num; i++) {
s += "0";
}
}
This is another loop using i without defining it. But since i was already defined as a global variable in the parent loop, this loop will be setting its value. So in short, the value of i is always equal to 6 - num in the parent loop. Since your exit condition is i < str.length, with a string of length 32 the loop will run forever.
You can get around this in many ways, one of which you've already posted. The other way would be to use let i or var i instead of i in the parent loop. Even better is to write something like this (but beware that padEnd may not work on old browsers):
function slicing(str) {
return str.match(/.{1,6}/g).map((item) => {
return item.padEnd(6, "0");
});
}
console.log(slicing("01000011010011110100010001000101"));

Need to filter out repeating consecutive characters in a string using JavaScript

It is one of the challenges in Codewars, and I am supposed to write a function that will take a string and return an array, in which I can't have two consecutive identical elements. Also, the order should not change.
For example, if I pass a string "hhhhheeeelllloooooohhheeeyyy", then the function should return an array = ["h","e","l","o","h","e","y"].
This is my code.
var uniqueInOrder=function(iterable){
//your code here - remember iterable can be a string or an array
var unique = [];
for( var i = 0; i < iterable.length; i++) {
unique.push(iterable[i]);
}
for( var j = 0, k = 1; j < unique.length; j++, k = j + 1 ){
if(unique[j] === unique[k]){
unique.splice(k,1);
}
}
return unique;
}
so, if I pass a string, such as "hhhhheeeeeellllloooo",it doesn't work as I intend it to because the value of j keeps incrementing, hence I can't filter out all the identical elements.
I tried tweaking the logic, such that whenever the unique[j] === unique[k] the value of j would become zero, and if that's not the case, then things would continue as they are supposed to do.
This got me an infinite loop.
I need your help.

The second for loop is fail because unique.length is not constant during the run.
I think your problem can be solved like this:
var temp = iterable[0];
unique.push(iterable[0]);
for( var i = 1; i < iterable.length; i++) {
if(iterable[i] != temp) {
unique.push(iterable[i]);
temp = iterable[i];
}
}
Hope it helps!

You only need to compare the current index of iterable against the last character in unique:
function(iterable){
var unique = []
for(var i=0; i< iterable.length; i++){
if(unique.length < 1){
unique.push(iterable[i])
} else if(iterable[i] !== unique[unique.length - 1]) {
unique.push(iterable[i])
}
}
return unique
}

I think this will help you:
var word="hhhhheeeelllloooooohhheeeyyy"
function doit(iterable){
var unique = []
unique[0]=iterable[0]
for(var i=1; i< iterable.length; i++){
if(iterable[i] !== unique[unique.length - 1]) {
unique.push(iterable[i])
}
}
return unique
}
alert(doit(word))
for loop will not fail because unique.length is dynamic, i.e will change with addition of new elements to array.
Tested in Internet Explorer too.
Here is the link to jsfiddle: https://jsfiddle.net/kannanore/z5gbee55/

var str = "hhhhheeeelllloooooohhheeeyyy";
var strLen = str.length;
var newStr = "";
for(var i=0; i < strLen; i++ ){
var chr$ = str.charAt(i);
//if(i==0) {newStr = chr$ };
if(chr$ == str.charAt(i+1)){
strLen = str.length;`enter code here`
}else{
newStr = newStr + chr$ ;
}
}
//document.write(newStr);
console.log(newStr);
//Answer: helohey

Understanding get second lowest and second highest value in array

Good day fellow Stack-ers,
I must ask your pardon if this question has been asked before or if it seems elementary (I am only a Javascript novice).
I have been doing w3c js challenges lately: Write a JavaScript function which will take an array of numbers stored and find the second lowest and second greatest numbers.
Here is my answer:
var array = [3,8,5,6,5,7,1,9];
var outputArray = [];
function arrayTrim() {
var sortedArray = array.sort();
outputArray.push(sortedArray[1],array[array.length-2]);
return outputArray;
}
arrayTrim();
and here is the answer that they have provided:
function Second_Greatest_Lowest(arr_num) {
arr_num.sort(function(x,y) {
return x-y;
});
var uniqa = [arr_num[0]];
var result = [];
for(var j=1; j < arr_num.length; j++) {
if(arr_num[j-1] !== arr_num[j]) {
uniqa.push(arr_num[j]);
}
}
result.push(uniqa[1],uniqa[uniqa.length-2]);
return result.join(',');
}
alert(Second_Greatest_Lowest([1,2,3,4,5]));
I know that the for loop runs through until the length of the input, but I don't understand the if statement nested within the for loop. It seems like a long way around to the solution.
Thank you!

Your answer does not perform correct for input such as f.e. [3,8,5,6,5,7,1,1,9]. Your proposed solution returns 1 as the second lowest number here – whereas it should actually be 3.
The solution suggested by the site takes that into account – that is what the if inside the loop is for, it checks if the current number is the same as the previous one. If that’s the case, it gets ignored. That way, every number will occur once, and that in turn allows to blindly pick the second element out of that sorted array and actually have it be the second lowest number.
It seems like a long way around to the solution
You took a short cut, that does not handle all edge cases correctly ;-)

The loop in question:
for(var j=1; j < arr_num.length; j++) {
if(arr_num[j-1] !== arr_num[j]) {
uniqa.push(arr_num[j]);
}
}
Provides some clue as to what it's doing by using a (reasonably) descriptive variable name: uniqa - or "unique array". The if statement is checking that the current element is not the same as the previous element - having sorted the array initially this works to give you a unique array - by only filling a new array if the element is indeed unique.
Thereafter the logic is the same as yours.

import java.util.Arrays;
public class BubbleWithMax_N_Min
{
public static void main(String[] agrs)
{
int temp;
int[] array = new int[5];
array[0] = 3;
array[1] = 99;
array[2] = 55;
array[3] = 2;
array[4] = 1;
System.out.println("the given array is:" + Arrays.toString(array));
for (int i = 0; i < array.length; i++)
{
System.out.println(array[i] + "");
}
for (int i = 0; i < array.length; i++)
{
for (int j = 1; j < array.length - i; j++)
{
if (array[j - 1] > array[j])
{
temp = array[j - 1];
array[j - 1] = array[j];
array[j] = temp;
}
}
}
System.out.println(" 2nd Min and 2nd Highest:");
for (int i = 0; i < 1; i++)
{
System.out.println(array[i+1]);
}
for (int i = 0; i < 1; i++)
{
int a= array.length-2;
System.out.println(array[a]);
}
}
}

I Want To Print 1 to 100 Numbers Using Arrays In Javascript Only

<!DOCTYPE html>
<html>
<head>
<title>100-Numbers</title>
</head>
<body>
<script>
var points = new Array(100);
var label = points.length;
for (var i = 0; i < label; i++) {
console.log(points[i]);
}
</script>
</body>
</html>
This is my First question in Stackoverflow. As i am an beginner, Please bare me and i need alot of support from you people. I m trying to print 1 to 100 numbers using arrays in javascript only. I'm Facing some errors in the above code. Please correct my mistakes to get the output..Thankyou in advance.

This will print 1-100 without any loops
Array.from({length: 100},(_,x) => console.log(x+1))

he said he wants to print 1-100 from an ARRAY...So the array needs to be populated, first. THEN, you can loop through the array.
var points = new Array(100);
for (var i = 0; i < 100; i++) {
points[i] = i + 1; //This populates the array. +1 is necessary because arrays are 0 index based and you want to store 1-100 in it, NOT 0-99.
}
for (var i = 0; i < points.length; i++) {
console.log(points[i]); //This prints the values that you stored in the array
}

The array values are uninitialized. I'm assuming that you want to print the values 1 to 100 using arrays where the values 1 to 100 are inside the array.
First initialize the array.
var oneToHundredArray = [];
Now populate it with values 1 to 100.
for(var value = 1; value <= 100; value++) {
oneToHundredArray.push(value);
}
Now the contains the values you want. Just loop and print over it now.
for(var index = 0; index < oneToHundredArray.length; index++) {
console.log(oneToHundredArray[index]);
}
Done :)

Array.from(Array(100), (_,i) => console.log(i+1));
The second parameter acts as mapping callback, so you also do this...
const arr = Array.from(Array(100), (_,i) => i+1);
for(num of arr) {
console.log(num);
}
Reference: Array.from

You should start off with an empty array, then run a loop for 1-101, I logged the iterator so you can see the values populate, you then need a binding agent to hold the value of the iteration, then you would need to push those values to your empty array.
var numbersArray = [];
for( var i = 1; i <101; i++){
console.log(i);
var numbers = i;
numbersArray.push(numbers);
}
After that, you then need to run a loop for the length of the numbersArray to output the individual results.
for(var m=0; m<= numbersArray.length -1; m++){
console.log(numbersArray[m]);
}
output console.log logs numbers 1-100 respectively.

var label = new Array(100);
for (var i = 0; i < 100; i++) {
label[i] = i + 1;
}
for (var i = 0; i < label.length; i++) {
console.log(label[i]);
}

It's much more easier with "while"
var i = 1;
while (i < 100) {
document.write(i + "<br/>");
i++;
}

Using a for loop:
function get_array() {
var arr = [];
for(var i=1; i<=100; i++) {
arr.push(i);
}
console.log(arr);
}
get_array()

Adding up all combinations of number in an array

I am trying to write a program in javascript that gets an unspecified number of numbers out of a html textarea and tries all combinations (adding all numbers with eachother) to see if it mathches a number you specified.
Now I can make an array out of the string in the textarea and using for loops I add these up (see below code). The problem how can you do this for an unspecified number of numbers that are to be added up (e.g. adding up 7 different number if you enter 7 numbers in textarea)? I was thinking of using a second array and, which gets the numbers to add up out of the first loop. And then make te lenght of the loop variable by using a for loop with the lenght of the array containing all numbers (lines in my example) as endvalue.
How can I fill in the values of this 2nd array, making sure all combinations are used?
By the way, I wanted this code because I am a auditor. Sometimes a client reverses a couple of amounts in one booking, without any comment. This code will make it a lot easier to check what bookings have been reversed
edit: The awnser of cheeken seems to be working I only have one remark. What if multiple sub sets of your power set added up result in the number you are looking for? e.g.:findSum([1,2,3,4,5],6) can result [1,2,3] but also [2,4] or [1,5]. is it possible to let the function return multiple sub sets?
Found the answer my self :)
I replaced code
return numberSet;
By
document.getElementById("outp").value=document.getElementById("outp").value+ numberSet +"\n";
Thank you very much Cheeken
One more additional question. How do i format the input for parsing that function? The code below doesn't seem to work. inp is the ID of the textarea where the input is (the numbers are seperated with a semicolumn. The variable ge works so there is no problem there (tested it with [1,2,3,4] and it worked. What is wrong with this code?
re edit:
found the solution. The array needed to be parsed as a floating number added this code.`
for (var i=0; i < lines.length; i++) {
lines[i]= parseFloat(lines[i]);
}
findSum(document.getElementById("inp").value.split(";"), ge);
Code:
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">
function powerset(arr) {
var ps = [[]];
for (var i=0; i < arr.length; i++) {
for (var j = 0, len = ps.length; j < len; j++) {
ps.push(ps[j].concat(arr[i]));
}
}
return ps;
}
function sum(arr) {
var total = 0;
for (var i = 0; i < arr.length; i++)
total += arr[i];
return total
}
function findSum(numbers, targetSum) {
var numberSets = powerset(numbers);
for (var i=0; i < numberSets.length; i++) {
var numberSet = numberSets[i];
if (sum(numberSet) == targetSum)
document.getElementById("outp").value=document.getElementById("outp").value+ numberSet +"\n";
}
}
function main()
{
ge= document.getElementById("getal").value;
findSum([1,1,0.5,0.1,0.2,0.2], ge);
}
</script>
</head>
<body>
<input type="button" onclick="main()" value="tel" /><input type="text" id="getal" /><br>
input<br><textarea id="inp" ></textarea><br>
output<br><textarea id="outp" ></textarea><br>
document.getElementById("inp").value.split(";")
</body>
</html>

More concretely, you're looking for a particular sum of each set in the power set of your collection of numbers.
You can accomplish this with the following bit of code.
function powerset(arr) {
var ps = [[]];
for (var i=0; i < arr.length; i++) {
for (var j = 0, len = ps.length; j < len; j++) {
ps.push(ps[j].concat(arr[i]));
}
}
return ps;
}
function sum(arr) {
var total = 0;
for (var i = 0; i < arr.length; i++)
total += arr[i];
return total
}
function findSum(numbers, targetSum) {
var numberSets = powerset(numbers);
for (var i=0; i < numberSets.length; i++) {
var numberSet = numberSets[i];
if (sum(numberSet) == targetSum)
return numberSet;
}
}
Example invocation:
>> findSum([1,2,3,4,5],6)
[1, 2, 3]
>> findSum([1,2,3,4,5],0)
[]
>> findSum([1,2,3,4,5],11)
[1, 2, 3, 5]
If you'd like to collect all of the subsets whose sum is the value (rather than the first one, as implemented above) you can use the following method.
function findSums(numbers, targetSum) {
var sumSets = [];
var numberSets = powerset(numbers);
for (var i=0; i < numberSets.length; i++) {
var numberSet = numberSets[i];
if (sum(numberSet) == targetSum)
sumSets.push(numberSet);
}
return sumSets;
}
Example invocation:
>> findSums([1,2,3,4,5],5);
[[2,3],[1,4],[5]]
>> findSums([1,2,3,4,5],0);
[[]]