How to Generate a random number of fixed length using JavaScript?

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I\'m trying to generate a random number that must have a fixed length of exactly 6 digits.

I don\'t know if JavaScript has given below would ever create a number less th

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被撕碎了的回忆

2021-01-30 10:40
```
npm install --save randomatic

var randomize = require('randomatic');
randomize(pattern, length, options);
```
Example:

To generate a 10-character randomized string using all available characters:
```
randomize('*', 10);
//=> 'x2_^-5_T[$'

randomize('Aa0!', 10);
//=> 'LV3u~BSGhw'
```
a: Lowercase alpha characters (abcdefghijklmnopqrstuvwxyz'

A: Uppercase alpha characters (ABCDEFGHIJKLMNOPQRSTUVWXYZ')

0: Numeric characters (0123456789')

!: Special characters (~!@#$%^&()_+-={}[];\',.)

*: All characters (all of the above combined)

?: Custom characters (pass a string of custom characters to the options)

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死守一世寂寞

2021-01-30 10:43

"To Generate Random Number Using JS"

console.log(
Math.floor(Math.random() * 1000000)
);

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript Math.random()</h2>

<p id="demo"></p>

</body>
</html>

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暗喜

2021-01-30 10:43

In case you also want the first digit to be able to be 0 this is my solution:

const getRange = (size, start = 0) => Array(size).fill(0).map((_, i) => i + start);

const getRandomDigit = () => Math.floor(Math.random() * 10);

const generateVerificationCode = () => getRange(6).map(getRandomDigit).join('');

console.log(generateVerificationCode())

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心在旅途

2021-01-30 10:45
generate a random number that must have a fixed length of exactly 6 digits:
```
("000000"+Math.floor((Math.random()*1000000)+1)).slice(-6)
```
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后悔当初

2021-01-30 10:45
```
const generate = n => String(Math.ceil(Math.random() * 10**n)).padStart(n, '0')
// n being the length of the random number.
```
Use a parseInt() or Number() on the result if you want an integer. If you don't want the first integer to be a 0 then you could use padEnd() instead of padStart().
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离开以前

2021-01-30 10:48
I created the below function to generate random number of fix length:
```
function getRandomNum(length) {
    var randomNum = 
        (Math.pow(10,length).toString().slice(length-1) + 
        Math.floor((Math.random()*Math.pow(10,length))+1).toString()).slice(-length);
    return randomNum;
}
```
This will basically add 0's at the beginning to make the length of the number as required.
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