Is there a simple jQuery way to create numbers randomly showing then a number 1 -6 is choosing after a few seconds? [Like dice]
This doesn't require jQuery. The JavaScript Math.random function returns a random number between 0 and 1, so if you want a number between 1 and 6, you can do:
var number = 1 + Math.floor(Math.random() * 6);
Update: (as per comment) If you want to display a random number that changes every so often, you can use setInterval to create a timer:
setInterval(function() {
var number = 1 + Math.floor(Math.random() * 6);
$('#my_div').text(number);
},
1000); // every 1 second
You don't need jQuery, just use javascript's Math.random function.
edit:
If you want to have a number from 1 to 6 show randomly every second, you can do something like this:
<span id="number"></span>
<script language="javascript">
function generate() {
$('#number').text(Math.floor(Math.random() * 6) + 1);
}
setInterval(generate, 1000);
</script>
function rollDice(){
return (Math.floor(Math.random()*6)+1);
}
Javascript has a random() available. Take a look at Math.random().
Coding in Perl, I used the rand() function that generates the number at random and wanted only 1, 2, or 3 to be randomly selected. Due to Perl printing out the number one when doing "1 + " ... so I also did a if else statement that if the number generated zero, run the function again, and it works like a charm.
printing out the results will always give a random number of either 1, 2, or 3.
That is just another idea and sure people will say that is newbie stuff but at the same time, I am a newbie but it works. My issue was when printing out my stuff, it kept spitting out that 1 being used to start at 1 and not zero for indexing.
Related
I am stuck on how my code will not be accepted by freeCodeCamp's auto-grader. The objective was to create a function without any parameters that will generate a random number using Math.random(). Then we would have to multiply the randomly generated number by 10. After multiplying the randomly generated by 10, I would have to use Math.floor() to round it up or down.
Link to challenge: https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-javascript/generate-random-whole-numbers-with-javascript
These are the objectives given to me, quoted directly from freeCodeCamp's challenge:
1.) The result of randomWholeNum should be a whole number.
2.) You should use Math.random to generate a random number.
3.) You should have multiplied the result of Math.random by 10 to make it a number that is between zero and nine.
4.) You should use Math.floor to remove the decimal part of the number.
Here is my code:
function randomWholeNum() {
var x = Math.random();
var z = x * 10;
var y = Math.floor(z);
return y;
}
As you can see, I used multiple variables to complete this task. x would generate the random number, z would store the random number multiplied by 10, y would round z, resulting in all objectives passed. However, when running the code, all objectives were ticked except for Number 3. I don't understand what went wrong, and after looking at the answer for the challenge, which is:
function randomWholeNum() {
// Only change code below this line.
return Math.floor(Math.random() * 10);
}
I don't understand why the code I wrote doesn't produce the same result of freeCodeCamp's own.
I'm making this acres and karats calculator for my uncle to help him in his work.
I'll explain the whole idea of this thing with this example. So if you add 3.22 + 2.2 it should be = 5.42 but in this calculator 3.22 + 2.2 should = 6, because 3 acres + 2 acres = 5 acres and 22 karats + 2 karats = 1 acre, so the total would be 6 acres.
The way I'm doing it in the code is that I'm splitting a number like 3.22 to two, 3 and 22 and the other number to 2 and 2 and I add the whole numbers together and the fractions together and if the fractions are >= 24 I add one to the whole numbers and if there're fractions left from the whole calculation I leave it. For example 3.15 + 2.15 = 6.6, but I'm stuck on how I can add the numbers, there's also an error in there that I don't know how to resolve.
Anyway here's the code
function getValue(v) {
return +v.toString().match(/\.(\d*)/)[1] || 0;
}
function getTotal() {
d += Math.floor(num);
p += getValue(num);
if (p >= 24) {
p -= 24;
++d;
}
total = d + p / 100;
ptag.textContent = total;
}
I added the part of the code where I'm stuck.
Note: I'm trying to make the thing able to add multiple numbers not only two. Also I'm trying to add subtraction but I have no idea how to start working on the subtraction because I haven't even finished the addition.
If the error you are talking about is something like this:
Uncaught TypeError: Cannot read property '1' of null
It is because of your getValue function.
My suggestion is, instead of using something as complicated as
function getValue(v) {
return +v.toString().match(/\.(\d*)/)[1] || 0;
}
use
function getValue(v) {
return floor((v % 1) * 100);
}
This has the same effect as the code you wrote. Which for example, from input 3.13, returns 13.
But there are few other problems.
First, you should update your num variable every now and often, otherwise, it is always going to stay as an empty string (you only defined it on line 20, and you didn't update it after that).
Second, you should clear the d and p variable after you use. As of right now, both of these variables just keeps on increasing every time you run the getTotal function
For your question of how you can add two numbers, I suggest you to create a variable where you can store the first number that the user typed.
For example, when the user typed in 4.19 and pressed the plus button, save that 4.19 into a variable (let's say firstNum).
Then when the user pressed equal button, add the number from the current input field with the firstNum variable.
On how exactly you are going to add two different numbers, break two numbers you want to add into Acres part and Karats parts. Then add them separately, then use your getTotal.
So if the number is 3.21 and 5.18, add 3 and 5, add 21 and 18, then add both of them.
you'll get 8.39. Finally, convert 8.39 into 9.15.
Sorry if my calculation is not correct. It is my first time with this concept!
But I believe this is the way to go.
I am new to JavaScript, I want to get the right page count.
if one page the item count is 20, and the page count is 23, the page should be 2.
var count = 23
var per_page_count = 20
If in other language we can use:
count / per_page_count + 1
to get the page count, but in JavaScript we can not get it.
I also tried use Math.round, still not work
console.log(Math.round(count/per_page_count)) // there I want to get 2, but get 1
You can use
Math.ceil(count/per_page_count)
The Math.ceil() function returns the smallest integer greater than or equal to a given number.
from Math.ceil document.
I think you are trying to implement some sort of pagination. So I would suggest :
Maths.ceil(count/per_page_count)
In the Code Academy JS course, Dragon Slayer 2/6, the following text is used in the hint to describe the order of operations for the code I included in the title.
How does this code work?
Math.floor(Math.random() * 5 + 1);
First we use Math.random() to create a random number from 0 up to 1. For example, 0.5
Then we multiply by 5 to make the random number from 0 up to 5. For >example, 0.5 * 5 = 2.5
Next we use Math.floor() to round down to a whole number. For example, >Math.floor( 2.5 ) = 2
Finally we add 1 to change the range from between 0 and 4 to between 1 and >5 (up to and including 5)
I've looked this up in several different places (here and here), and a majority of them either focus on the range that Math.random() produces (which I understand) or confirm the order of operations outlined in the hint, wherein "Math.floor" acts upon "Math.random()*5" prior to the "+1" being added.
It seems to me however that, according to the order of operations that I learned in school, the last two steps should be flipped. Would that not be the case since "Math.random()*5" and the "+ 1" are both within the parenthesis?
While the difference between these two might not make a difference in the value returned from this particular code, I could see a fundamental change in the order of operation like the one outlined here would cause me some frustration further down the road if I didn't know it.
Math.floor() will work on whatever is inside the brackets, after it has been calculated.
Math.floor(Math.random() * 5 + 1)
is the same as
var i = Math.random() * 5;
i += 1;
Math.floor(i);
You are correct that the wording on the page is wrong. The last thing that will happen is the floor call. Everything in the parenthesis will be processed first.
Honestly, I think they mixed up here, and you're right. According to PEMDAS and any mathematics I've ever learned, the +1 comes before the Math.floor function.
The Math.random() function returns a random number in the range [0, 1) that is, from 0 (inclusive) up to but not including 1 (exclusive). It can be any thing like 0,.34,.42 etc.
if you want random number between 0-5.
you will used Math.Random()*5. This will give you any number like 0,4.43.4.34 but not five.
Then we add 1 like this Math.random() * 5 + 1. Now the chances is you will get a number which is between 0 and 6. But you don't want number above 5. so
you apply floor method which will return largest integer less than or equal to a given number.
I have a simple little javascript count up timer on my page that I want to tweak, but really don't know where to begin.
The goal is that instead of it counting straight up in timed intervals is to have it jump randomly upward.
for example, if my timer is showing 100 and is set to increase again in 1 second, instead of it showing 101, I want it to show some random number between 101 & 106.
Any nods in the right direction would be greatly appreciated.
I appreciate the help you guys gave me (posts 1&2) ... but i'm still missing it somehow.
Here is the link to what i currently have... http://jsfiddle.net/FQSAH/19/
As you see it run, it's moving up by 1, but i'm wanting it to move up by a random number between 1&5 each time.
var x = 0;
setTimeout(function() {
// random interval between 1 and 10
var interval = Math.floor((Math.random() * 10) + 1);
x += interval;
}, 1000);
Tweak 10 as large as you want for a higher variability in intervals.
With a setInterval() you could schedule a function to run every second.
To get the random effect working, you could create a function to update a variable using Math.random().
For example:
var value = 0;
function randomize() {
value += (1 + (Math.random() * 5)); //random value between 1 and 5
}
setInterval(randomize, 1000);