For loop homework - javascript

I have homework and these are my instructions:
create javascript 06.js with a general function: addThemUp()
There is NO HTML page. There is NO EVENT HANDLER.
The function receives two parameters. They go between (..).
Use any names you want for the parameters but you could use descriptive names
Add all integers from the first parameter to the second.
All you need to do is use a for() loop and return the total.
Return the total of the integers. Use return because this is a general function.
Here is my code
function addThemUp(earlier,later) {
var total = 0;
for (i = 0; i <= earlier; i ++) {
total = total + 0;
};
return total;
};
For some reason this one is messing up bad. We were able to do this exact same thing with Count but adding up and array seems to be different. When I run it through the grader I'm only receiving 25% grade.

You need to make use of both earlier and later in your loop:
function addThemUp(earlier,later) {
var total = 0;
for (i = earlier; i <= later; i ++) {
total = total + i;
};
return total;
};

Shouldn't it be using
i <= later
As it would stop on the first value otherwise?

I'll point out two things that could help you on your way.
First: this line
total = total + 0;
Think about what it's doing for a bit.
total (which starts as 0) is adding... 0... to itself. ;)
Next, this line:
for (i = 0; i <= earlier; i ++) {
IIRC, earlier is the first of the two numbers you're concerned about.
That part of the for loop says "stop when this condition is met." ;)

Related

'For loop' within a function

I hope everyone is having an amazing day so far.
I am asking for help on an exercise that I am stuck on. I have gone through and researched all over but still am not getting it right.
The task is:
Create a for loop in which an iterator starting from 0 up to the iteratorMax value (not included) (the second parameter to your function) is incremented by 1. Add the iterator to num(the first parameter to your function) for each incrementation. you must return the number at the end of your function.
I was given this code to start with:
function IncrementNumber(num, iteratorMax){
//Add For loop here
//return value here
}
I have tried coding it a number of different ways but still not correct.
for example:
function IncrementNumber(num, iteratorMax){
for (let i = 0; i < iteratorMax; i++) {
return(i);
}
}
I have tried to declare "i" but that seems to be incorrect also.
I really appreciate any help or hints to what I am missing or doing wrong in my code.
Thank you!
For the IncrementNumber(value, N) method, when value is 0, this algorithm returns the result of the equation:
Total = N x (N-1) / 2
function IncrementNumber(num, iteratorMax){
for(let i = 0 ; i < iteratorMax ; ++i){
num += i;
console.log(`i: ${i}\tnumber: ${num}`);
}
return num;
}
console.log(`Result: ${IncrementNumber(0, 10)}`);
If you call return within the loop, the loop will only be executed once.
You need to move the return statement outside of the loop.
Whenever calling return, this will cause the current function to exit.
function IncrementNumber(num, iteratorMax){
for (let i = 0; i < iteratorMax; i++) {
num += i;
}
return num;
}

Code is getting stuck somewhere in a succession of for-loops and I'm not sure why

EDIT - I changed the code to correctly declare variables below but nothing seems to have changed
I've written code using a for-loop that has to satisfy a number of criteria before executing what's within it. The problem is that, somewhere along the way, the code is getting stuck inside one of the loops, causing the computer to crash.
I've tried breaking the loop but this doesn't seem to help.
function compareKeypoints(varifiedKeypoints) {
outer_loop: for (i = 0; i < varifiedKeypoints.length; i++) {
let initialKeypoint = varifiedKeypoints[i];
for (j = 0; j < varifiedKeypoints.length; j++) {
let comparisonKeypoint = varifiedKeypoints[j];
if (initialKeypoint.part != comparisonKeypoint.part) {
if (Math.abs(comparisonKeypoint.position.x - initialKeypoint.position.x) <= 20
&& Math.abs(comparisonKeypoint.position.y - initialKeypoint.position.y) <= 20) {
if (keypointsCompatible(initialKeypoint.part, comparisonKeypoint.part)) {
console.log("Activating part: " + initialKeypoint.part);
console.log("Activated part: " + comparisonKeypoint.part);
let keypointPair = {
point_1: initialKeypoint.part,
point_2: comparisonKeypoint.part
}
console.log("Pushing parts!");
activeParts.push(keypointPair);
console.log("breaking loop!");
break outer_loop;
console.log("Loop NOT broken!!");
}
}
}
}
}
if (activeParts.length > 0) {
console.log(activeParts);
}
}
function keypointsCompatible(keypoint_1, keypoint_2) {
var outcome = true;
if (activeParts.length > 0) {
compatibility_loop: for (i = 0; i < activeParts.length; i++) {
if (Object.values(activeParts[i]).includes(keypoint_1) && Object.values(activeParts[i]).includes(keypoint_2)) {
console.log(keypoint_1 + " and " + keypoint_2 + " are not compatible because they already exist as " + activeParts[i].point_1 + " and " + activeParts[i].point_2 + " respectively");
outcome = false;
break compatibility_loop;
console.log("Compatibility NOT broken!!");
}
}
}
console.log("Compatibility outcome is " + outcome);
return outcome;
}
The code is suppose to take two values in the same array and compare them. If a number of conditions are met, including if they're a certain distance apart from one another, they will be pushed into a secondary array. If the values already appear in the secondary array, which the keypointCompatible function is suppose to determine, the loop should either continue looking for other candidates or stop before being called again. For some reason, however, the code is getting stuck within the keypointCompatible function when it detects that the values have already appeared in the secondary array and the console will repeatedly print "Compatibility is false" until the browser crashes.
Working Solution
Use let or const instead of var or nothing. Your issue may be related to closures and variables reused between loops. Make sure you use let or const in your loops too. for (let i=0).
When you use let or const, the runtime will create a new instance every time the block or loop iterates. However, using var will reuse the internal allocation.
So what happens with the standard var is the multiple closures or loops each use the same instance of the variable.
Unless you want the var behavior, always use let or const.
Another Solution
Put a newline after the label compatibility_loop
Still Another Solution
The first function is pushing into activeParts. The second function is looping activeParts. This can go on forever, or longer than expected. Pushing into the array could possibly make the loop limit never reached.
Put a log on the length of activeParts in the second function to see if it is growing out of control.
Your code should be OK if varifiedKeypoints.length has reasonable value. And all internal variables are declared properly!
You have two loops (this inner can start at j=i+1 to save time and multiple calculations) with few conditions inside.
function compareKeypoints(varifiedKeypoints) {
outer_loop: for (let i = 0; i < varifiedKeypoints.length; i++) {
let initialKeypoint = varifiedKeypoints[i];
for (let j = i+1; j < varifiedKeypoints.length; j++) {
let comparisonKeypoint = varifiedKeypoints[j];

I'm having trouble with this exercise on hacker rank please look

https://www.hackerrank.com/contests/projecteuler/challenges/euler001
Here is the problem I'm confused what the parseInt readline statement
and also the the var n statement mainly..
when i run my code it seems to count up to ten twice probably a simple problem just not seeing it and was hoping I could get it explained so I can keep working on project euler problems
Thanks
function main() {
var t = parseInt(readLine());
var sum = 0;
var arr = [];
for(var a0 = 0; a0 < t; a0++){
var n = parseInt(readLine());
for (var i = 0; i < n; i++)
if (i % 3 === 0 || i % 5 === 0){
arr.push(i);
sum += i;
};
console.log(arr);
};
}
Maybe I'm not following exactly what is your question.
The parseInt is a javascript function.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseInt
The readLine() function is defined for you, it will give you "the next line" that was captured from standard in.
All (or most) of the hackerrank problems offer the input for the problem thru standard-in and expect the result from standard-out. So for this problem, hackerrank has created this boilerplate code for reading that input.
process.stdin.on('end', function () {
input_stdin_array = input_stdin.split("\n");
main();
});
There is filling the input_stdin_array array that is used on the readLine() function.
And about the
when i run my code it seems to count up to ten twice
The problem mentions:
First line contains T that denotes the number of test cases. This is followed by T lines, each containing an integer, N.
So you are printing the array T times (for the default test case is 2), so that why you probably see the "up to ten 2 times"
I hope this helped, and probably you could start with a couple of the https://www.hackerrank.com/domains/tutorials/30-days-of-code challenge so you get a better grasp of how to work on the problems.
Regards
Declare the array after the first for loop. You are using the same array for every test case, even though it still contains numbers from the previous test cases. Same for the sum.
for(var a0 = 0; a0 < t; a0++) {
var arr = [];
var sum = 0;

How to sort elements of array in natural order with mixed (letters and numbers) elements

i am trying to create google-form which is used to register students agreements on practice. Every agreement is registered and got agreement number which format is Last to digits of current year-T-number of agreement at this year/M. For example for now it is 17-T-11/M. The number of agreement currently is written by person which is responsible for practice.
Here is code of script below:
function onChange(e)
{
var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheets()[1];
var range = sheet.getDataRange();
var values = range.getValues();
var comboValues = ['16-T-105/M'];
// removing titles from 0 column and 1 line (titles)
for (var i = 1; i <= values.length; i++) {
var v = values[i] && values[i][0];
v && comboValues.push(v)
}
// Sort the values
comboValues.sort(
function(a, b) {
if (b.toLowerCase() < a.toLowerCase()) return -1;
if (b.toLowerCase() > a.toLowerCase()) return 1;
return 0;
}
);
Logger.log(comboValues);
// google-form modification
var form = FormApp.openById('1SHgVIosoE34m9cny9EQySljvgnRpzffdFEZe-kzNOzA');
var items = form.getItems();
for (i = 4; i < items.length; i++) {
Logger.log("ID: " + items[i].getId(), ': ' + items[i].getType());
}
form.getItemById('2087613006').asListItem().setChoiceValues(comboValues);
I got issue which is related with lexicographical order. Person which register agreement choose from list last registered agreement number: i tryed to do that last registered agreement number will always be at list top. As time when i started this everything was fine (it started with number 16-T-105/M), but new year come and soon after 17-T-10/M agreement was registered i got issue, that 17-T-10/M was not on list top. Soon i realised that this happens because script use lexicographical order and "thinks" that 2 is more than 10. So i understood that i somehow will have to change that order and do that 2 is less than 10, 11 is less than 101 and so on.
My question is how to do that? I guess that i need to sort array elements in natural order - but i do not have idea how to do this.
I tryed to google how to do it , but result was not satisfactory - maybe my knowledge of coding is pretty limited (i am PhD student of Psychology, not Informatics) :)
Maybe someone will help how to solve that problem.
Updates:
Link to spreadsheet: https://docs.google.com/spreadsheets/d/1FH5qYTrLUNI2SCrcaqlwgu8lzAylaTkZsiALg0zIpCM/edit#gid=1620956794
Link to google-form (Copy of actual form): https://docs.google.com/forms/d/e/1FAIpQLSerJfkv1dgHexUwxppXNyhb46twOZgvEMOIVXSOJoED3SLmyQ/viewform
You should adjust the sorting method to account of the peculiarities of the data. Here is one way to do this: the function splitConvert processes each string, splitting it by non-word characters and then converting what can be converted to integers (and lowercasing the rest). Then the comparison goes through this array one by one.
comboValues.sort(
function(a, b) {
var as = splitConvert(a);
var bs = splitConvert(b);
for (var i = 0; i < as.length; i++) {
if (bs[i] < as[i]) return -1;
if (bs[i] > as[i]) return 1;
}
return 0;
}
);
function splitConvert(str) {
return str.split(/\W/).map(function(part) {
var x = parseInt(part, 10);
return isNaN(x) ? part.toLowerCase() : x;
});
}
This is not the most performance-oriented solution: the split-parse function will be repeatedly called on the same strings as they are being sorted. If this becomes an issue (I don't really think so), one can optimize by having one run of conversion, creating an array of arrays, and then sorting that.

Include duplicates in for and if loop of array as count number is too small

I'm new to javascript so any help would be greatly appreciated.
What I'm trying to do is cycle through every element in the array and count the number of times the value of an element matches a given condition (even if the value is duplicated).
function loaddata(xml) {
var count = 0;
var i;
var xmlDoc = xml.responseXML;
var z = xmlDoc.getElementsByTagName("group");
if (value1 <= value2) {
for (i = 0; i < (0 + z.length); i++) {
if (z[i].getElementsByTagName("name")[0].childNodes[0].nodeValue == "John") {
count++;
}
}
}
$('#count1').html(count);
};
The count value outputted is too small. I believe the reason for this that the for loop isn't iterating through all elements in the array. When I remove the second if loop and output the count for just the for loop this value is also too small. I believe that the for loop isn't searching through the duplicate elements of the array (i.e. it is ignoring them so that they aren't then fed into the second if loop). Is it possible to specify that the for loop include duplicates?
Do a console.log(z[i].getElementsByTagName("name")) and open your browser's console, and see if that array has data in it.
Then console.log(z[i].getElementsByTagName("name")[0].childNodes) and make sure you have nodes in it.
Also, do you have many <group></group> tags? Because that's what you are selecting with var z = xmlDoc.getElementsByTagName("group");
I hope that helps,

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