Recently, I have to write a program which, when I have received 5 values in my document.write, the program has to start on a new line.
I searched on multiple things on the internet and I found nothing about it. Here I show you how to deal with it. Hope it can help you!
var countr = 0;
for(i = 1; i <= 50; i++) {
document.write(i+" ");
compteur++;
if (count === 5) {
document.write("<br>");
count = 0;
}
}
You want to use i % 5 === 0 -- Modulus will calculate the remainder. Use in an if statement to write <br> when it returns 0.
//var countr = 0;
for (i = 1; i <= 50; i++) {
document.write(i + " ");
// compteur++;
if (i % 5 === 0) {
document.write("<br>");
// count =0;
}
}
Since you're using a loop, you can use i in your comparison as long as you don't update the variable. You're also using countr, compteur, count while you can use i instead. // comments (disables) code.
I don't understand exactly what result you are expecting. But at first what I see - you have written your counter incorrect 3 times.
var counter= 0;
for(i=1 ; i<=50 ;i++){
document.write(i+" ");
counter++;
if (counter === 5){
document.write("<br>");
counter =0;
}
}
Related
Consider the following for loop (and assuming we don't know 3 times table - i.e. how many results might occur).
<script summary>
function myFunction() {
var output_text = "";
var i;
for (i = 0; i < 20; i++) {
if (Number.isInteger(i/3)){
if ("e.g. this is the last index?") {"e.g.then do this?"
output_text += "This number is the last " + i ;
}else{
output_text += "The number is " + i + "<br>";
}
}
}
}
</script>
Trying to 'output_text' as something like:
The number is 0
The number is 3
The number is 6
The number is 9
The number is 12
The number is 15
The number is the last 18
Any ideas for how to catch that last loop iteration.
This is just an example as actual application is a bit wordy - but the concept is the same.
I could run a count first to get index length, but wondered if there is an easier way.
Many thanks for anyone's time. Also first go at posting - any advice welcome.
Just add 3 to the current index and check if it exceeds 19.
function myFunction() {
var output_text = "";
var i;
const max = 19;
const factor = 3;
for (i = 0; i <= max; i++) {
if (i % factor === 0){
if (i + factor > max) {
output_text += "This number is the last " + i ;
}else{
output_text += "The number is " + i + "<br>";
}
}
}
return output_text;
}
document.write(myFunction());
If you have a number divisible by 3, perform a second check to see if 20 minus i < 3 and you'll know if it's the last number.
function myFunction() {
var output_text = "";
for (var i = 0; i < 20; i++) {
if (Number.isInteger(i/3)){
if (20 - i < 3) {
output_text += "This number is the last " + i ;
}else{
output_text += "The number is " + i + "<br>";
}
}
}
document.getElementById("out").innerHTML = output_text;
}
myFunction();
<div id="out"></div>
The better approach is to show result of current iteration in the next iteration. In this case, last iteration will not be handled in the loop. So, you can handle it after easily.
I'm making a small script that will iterate the numbers and skip the number 5. I want to achieve this with continue; statement/label.
Here is my code:
<p id="test"></p>
<script>
var i, text;
text = "";
i = 0;
for (;i<8;) {
if (i === 5) {continue;}
text += "The number is " + i + "<br>";
i++;
}
document.getElementById('test').innerHTML = text;
</script>
I'm failing to see any typo error, but coding for more than 12 hours now, maybe I'm overseeing something obvious. If so, I apologize.
This works when I want to stop at number 5 using break; statement.
<p id="test"></p>
<script>
var i, text;
i = 0;
text = "";
for (;i<8;) {
if (i === 5) {break;}
text += "The number is " + i "<br>";
i++;
}
document.getElementById('test').innerHTML = text;
</script>
if (i === 5) {continue;}
will never allow the control to go ahead and increment the i. Thus, it'll always go back when i becomes five.
Solution:
if (i === 5) {
i++; // Increament `i` first
continue;
}
OR, using for third argument.
for (; i<8; i++) {
^^^ // Increment `i` for each iteration
One more simple thing can be done using if condition.
for (; i < 8; i++) {
// If i is not 5, then only append to the string.
if (i !== 5) {
text += "The number is " + i + "<br>";
}
}
This is causing an infinite loop as your value is never being incremented. continue will move onto the next iteration, however since you haven't defined a statement to increment your value, this never occurs.
Consider refactoring your loop as follows as opposed to performing your incrementation within the body of the loop:
<script>
var text = "";
// This is the most common approach to defining a for-loop as it handles defining
// your iterator, defining a stop condition and handles how to increment your value
// after each iteration
for (var i = 0; i < 8; i++) {
if (i === 5) {break;}
text += "The number is " + i "<br>";
}
document.getElementById('test').innerHTML = text;
</script>
if (i === 5) {continue;}
When i is 5 it never gets a chance again to reach i++. So, i will ever be 5 and you will never exit the loop.
How to do two variables in an if condition? Here I have few else ifs and I want a 100 else ifs! Is there a shorter way?
$(document).on('click', '.btn-next', function () {
var z = [];
var recipientsArray = z.sort();
var zDuplicate = [];
$('option:selected.exclude_global').each(function() {
z.push($(this).val())});
for (var i = 0; i < recipientsArray.length - 1; i++) {
if (recipientsArray[i + 1] == recipientsArray[i]) {
zDuplicate.push(recipientsArray[i]);
}else if(recipientsArray[i + 2] == recipientsArray[i]){
zDuplicate.push(recipientsArray[i]);
}else if(recipientsArray[i + 3] == recipientsArray[i]){
zDuplicate.push(recipientsArray[i]);
}else if(recipientsArray[i + 4] == recipientsArray[i]){
zDuplicate.push(recipientsArray[i]);
}
}
if(zDuplicate.length>>0){
alert("Global Filter Already Exists");
event.preventDefault();
}
});
Here I have few else ifs and I want a 100 else ifs! Is there a shorter way? I have a dynamic table with dynamic rows. when my table has 5 rows the code is working, but when I have more its not working.
What you're looking for is called a nested loop. You basically can write a loop within a loop. (As many as you want, actually. Though it can get ugly fast.)
Consider your loop structure:
for (var i = 0; i < recipientsArray.length - 1; i++) {
// check if recipientsArray[i] equals any other element
}
Well, that's just another loop:
for (var i = 0; i < recipientsArray.length - 1; i++) {
for (var j = i + 1; j < recipientsArray.length - 1; j++) {
if (recipientsArray[j] == recipientsArray[i]) {
zDuplicate.push(recipientsArray[i]);
break;
}
}
}
Note that there's probably a more efficient way of checking for duplicates. (Especially if the collection is sorted.) At the very least I've changed the logic so you're not re-comparing comparisons you've already made. (I did this by starting the inner loop at i + 1 instead of 1 as your logic does.)
I also think I've replicated your else if results by using a break statement. Since your else if logic basically means "once you find one, stop looking". That's what this break should do, or at least is intended to do, but you'll want to test that. If it doesn't (nesting can be confusing sometimes, which is why it should be done carefully) then you can probably make use of labels to achieve the same effect.
Ultimately, however you implement it, the concept is the same. You're asking how to iterate over multiple values in an array. That's what a loop is for.
I don't know that language. But data and control structures are data and control structures in any language.
Substitute your for loop by :
for (var i = 0; i < recipientsArray.length - 1; i++) {
for ( var j = i+1; j < recipientsArray.lenght-1; j++) {
if (recipientsArray[i] == recipientsArray[j]) {
zDuplicate.push(recipientsArray[i]);
break;
}
}
}
Thank you so much for the idea!
A small change to your code works like heaven!
for (var i = 0; i < recipientsArray.length - 1; i++) {
for (var j = 1; j < 100; j++) {
if (recipientsArray[i+j] == recipientsArray[i]) {
zDuplicate.push(recipientsArray[i]);
break;
}
}
}
Trying to create a function or two that will be able to check the elements of an array and output wheater the elements of the two arrays are identical (ie same number and identical position is present), or the number is present but does not match the same position as the other array. Basically, I'm attempting to recreate a simple game called mastermind. The main problem im having is a case senarior when say the right answer is [1,2,3,4] and the user will guess [0,1,1,1], my function will out put that the number 1 is present 3 times, and I need to figure out how to just have it say the number 1 is present 1 time. Here is the function that checks the arrays:
function make_move(guess, answ){
var myguess = document.getElementById("mymoves");
var correct_number_correct_spot= 0;
var correct_number_wrong_spot= 0;
for(var i = 0; i < 4; ++i)
{
if(answ[i] == guess[i]){
++correct_number_correct_spot;
}
else if(answ[i] !== guess[i] && $.inArray(guess[i], answ) !== -1){
++correct_number_wrong_spot;
}
}
console.log(answ);
console.log(guess);
myguess.innerHTML += correct_number_correct_spot + " were right!" +correct_number_wrong_spot+ "there but not in the right order";
}
You can keep the count of missed numbers in an object, and subtract the guessed ones that appear in the answer. Then you can calculate the correct_number_wrong_spot subtracting the number of correct_number_correct_spot and the missed ones.
function make_move(guess, answ){
var myguess = document.getElementById("mymoves");
var correct_number_correct_spot = 0;
// Initialize missed counts to the numbers in the answer.
var correct_number_wrong_spot = answ.length;
var missed = {};
for (var j = 0; j < answ.length; j++) {
missed[answ[j]] = (missed[answ[j]] || 0) + 1;
}
for(var i = 0; i < answ.length; ++i)
{
if(answ[i] == guess[i]){
++correct_number_correct_spot;
}
// Subtract the guessed numbers from the missed counts.
if (guess[i] in missed) {
missed[guess[i]] = Math.max(0, missed[guess[i]] - 1);
}
}
// Subtract the correctly spotted numbers.
correct_number_wrong_spot -= correct_number_correct_spot;
// Subtract the remaining missed numbers.
for (var number in missed) {
correct_number_wrong_spot -= missed[number];
}
console.log(answ);
console.log(guess);
myguess.innerHTML += correct_number_correct_spot + " were right!" +correct_number_wrong_spot+ "there but not in the right order";
}
Check demo
EDIT: My try to explain doubts exposed in the comments:
would you mind explining how this code works: for (var j = 0; j < answ.length; j++) { missed[answ[j]] = (missed[answ[j]] || 0) + 1; }
missed[answ[j]] = (missed[answ[j]] || 0) + 1;
This is a quick way to increment the count for a number or initialize it to 0 if it doesn't exists yet. More or less the statement works like this:
If missed[answ[j]] is undefined then it is falsy and hence the || (or operator) evaluates to the 0. Otherwise, if we already have a value greater than 0, then it is truthy and the || evaluates to the contained number.
If it looks weird, you can replace this line with:
if (!(answ[j] in missed)) {
missed[answ[j]] = 0;
}
missed[answ[j]] += 1;
also if (guess[i] in missed) { missed[guess[i]] = Math.max(0, missed[guess[i]] - 1);
missed[guess[i]] = Math.max(0, missed[guess[i]] - 1);
In this case I use Math.max to make sure we don't subtract below 0. We don't want repeated numbers in the guess that exceeds the number of those present in the answer count. I mean, we subtract at most until the number of repeated numbers in the answer.
if (missed[guess[i]] > 0) {
missed[guess[i]] -= 1;
}
Try this fiddle!
Without changing your original function too much, you can use an object as a map to keep track of which numbers you have already matched.
var number_matched = {};
// ...
if(!number_matched[guess[i]]) {
number_matched[guess[i]] = true;
}
I'm pretty new to to javascript so please take it easy :)
I'm trying to figure out the probability of 10 people picking the same random number (1 - 20).
When I run the code it returns the same answer every time. I think something is wrong in the 3rd for loop when comparing numbers. Some help would be much appreciated, I've been stuck on this for 3 days now :(
var counter = 0;
//Determine probability (percentage)
for (var i = 1; i <=100; i++) {
//Create array with 10 elements and assign each element with random integer (1 - 20)
for (var j = 1; j <= 10; j++) {
var rndNum = [j];
rndNum = Math.random();
rndNum = Math.floor(rndNum * 20) + 1;
}
//Increment counter if match is found
for (var p1 = 1; p1 <= 9; p1++) {
for (var p2 = p1 + 1; p2 <= 10; p2++) {
if (rndNum[p1] == rndNum[p2]) {
counter++;
}
}
}
}
document.write("The probability of a match is: " + counter + "%");
Your code to make an "array" of random numbers is part of the problem. rndNum only has one value (it's an array with only one item in it, and you're overwriting it each time). You need array.push() to add values to an array.
You want something more like this:
var rndNum = [];
for (var j = 1; j <= 10; j++) {
rndNum.push(Math.floor(Math.random()* 20) + 1);
}
You want to know the probability that twenty people will pick the same random number?
alert("The probability of a match is: " + (Math.pow(.1, 20)*100)+ "%");
Or you want to know the probability that any two of twenty people will pick the same number?
alert("The probability of a match is: " + (Math.pow(.9, 20)*100)+ "%");
Your for loop should also start at 0, not one (the first element in an array is array[0]:
for (var p1 = 0; p1 <= 8; p1++) {
for (var p2 = p1 + 1; p2 <= 9; p2++) {
if (rndNum[p1] == rndNum[p2]) {
counter++;
}
}
}
You also need to divide your results by 10 because you have 1,000 tests (if you're checking to see if two match). If you want to see if they all match you would need something like:
var ordered = rndNum.sort();
if(ordered[0] == ordered[9])
counter2++;
Here's a fiddle of the combined array declaration and match checkers.