Creating a random number for a local storage keyName-CodePudding

I am trying to create a random number as the keyName for a local storage for example in this code: localStorage.setItem('_8bcsk999r778311o', input.value); I want to create a random number in the place of "_8bcsk999r778311o" using javascript . Is it possible , and if possible , could you please send me the code? Thanks in advance!

CodePudding user response：

const random_id = `_${Math.random().toString(30).substr(2,17)   Math.random().toString(30).substring(2,17)}`
console.log(random_id)

//localStorage.setItem(random_id, 'value goes here');

Very simple and fast solution

CodePudding user response：

Takes a number from 1 to 10 and save into number then with floor convert number to integer

//random integer from 0 to 10000:
let number = Math.floor(Math.random() * 10000);
localStorage.setItem(number, input.value);

In JavaScript, floor() is a function that is used to return the largest integer value that is less than or equal to a number. see more

Math.random() returns a random number between 0 (inclusive), and 1 (exclusive): see more

CodePudding user response：

var key = "";
var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

for (var i = 0; i < Math.floor(10 10*Math.random()); i  ) {
    key  = possible.charAt(Math.floor(Math.random() * possible.length));
}
localStorage.setItem(key, input.value);

I hope this will be helpful for you. Thanks.

CodePudding user response：

You could utilise the random nature of the window.crypto object to deliver your numeric / string IDs with a simple function as below. By tweaking the input arguments you can easily generate either numeric or alphanumeric strings of varying sizes.

Uint32Array

crypto.getRandomValues()

const uniqid = (length = 2, base = 16) => {
  let t = [];
  // invoke the crypto
  let crypto = window.crypto || window.msCrypto;
  // create a large storage array
  let tmp = new Uint32Array(length);
  // populate random values into tmp array
  crypto.getRandomValues( tmp );
  
  // process these random values
  tmp.forEach(i => {
    t.push( Math.floor( i * 0x15868 ).toString( base ).substring( 1 ) )
  });
  
  return t.join('');
}



// purely numeric using Base10
console.info( 'Numeric - Base 10: %s', uniqid(2, 10) );
console.info( 'Long Numeric - Base 10: %s', uniqid(4, 10) );

// Alphanumeric strings using Base16
console.info( 'Alphanumeric String - Base 16: %s', uniqid(2, 16) );
console.info( 'Long Alphanumeric String - Base 16: %s', uniqid(4, 16) );