How to use "Math.random()" to generate a random number in JavaScript?
I have started doing the coding in JavaScript programs some months ago. Now I can make a better programs in JavaScript. The problem I am facing now is while using the Math.random(). Can anyone explain me how to use "Math.random()" to generate a random number..?? I have tried a lot of different things but was not successful. The sample of coding will be appreciable. Expecting some help as soon as possible.!
Re: How to use "Math.random()" to generate a random number in JavaScript?
If you want to generate a random number between 1 and 200, you can do this by using the random() method. Use the following code for better explanation :
Code:
var rand_no = Math.random();
rand_no = rand_no * 200;
alert(rand_no);
The first step is to multiply the long decimal random number generated by the random() method with 200. The code above will give us a random number between 0 and 10. All numbers will be a little more than 0 and a little less than 200.
Re: How to use "Math.random()" to generate a random number in JavaScript?
I would like to suggest you to use the JavaScript ceil() method. By using this method, you can round a decimal number to the next higher integer. Check the following example that demonstrates the same :
Quote:
Math.ceil(3.357) -->gives 4
Math.ceil(32.98)-->gives 33
Math.ceil(1.006)-->gives 2
JavaScript generates random numbers based on a formula. Hope that you will get something useful from this.
Re: How to use "Math.random()" to generate a random number in JavaScript?
While creating the applications in JavaScript like dice, random image script, or random link generator, a random number plays an important role. If you want to generate a random number in JavaScript, you can use the mentioned code :
Code:
var randomnumber=Math.floor(Math.random()*101)
In the above coding 101 indicates that the random number will fall between 0-100. You can change the number accordingly.
Re: How to use "Math.random()" to generate a random number in JavaScript?
Whenever you need a random number, you can use the "Math.random()" every time. Also the main thing in Math.random() is that you have to set the range. Check the following example where I have used it.
Code:
now = new Date();
seed = now.getSeconds();
var random_number = Math.random(seed);
var range = random_number *10;
The above code will begin at 0 and will end with 9. This is the only reason why we are multiplying the random_number with 10. If your "random_number" equalled .5026 and multiplying by 10 gives us 5.026. The overall range of numbers to the left of the decimal point will now be the 0 - 9. You will get the option 0-99 if you multiply by 100.
Re: How to use "Math.random()" to generate a random number in JavaScript?
If you want to generate the random numbers from a given range, follow the steps for that :
- First you will have to get the number between 0 and 10 from random() method.
- After that you will have to multiply that number with the difference of upper value and one less than the lower value of the range.
- For converting that into an integer. you will have to use floor().
- Lastly add the lower value of the range.
Check the following example :
Code:
var rand_no = Math.floor((20-9)*Math.random()) + 10;
alert(rand_no);
The code above generates a random number between 10 and 20.