Algorithm to convert any string to a 1-3 digit number

Question

I want to make an algorithm, for a NodeJS app, that converta any given string to a 1 to 3 digit number (better if the number is between 1-500).

e.g
ExampleString -> 214

Can anyone help me find a good solution?

EDIT: I want to get a crime coefficient number from a username (string).

How should we know how to convert the strings? What's on your mind? What have you tried? — ibrahim mahrir, Feb 20 '17 at 17:05
You have to give us some clue what problem you're actually trying to use this for so we know how to best go about it. Without the limitation of 1-500, we could just calculate a hash of the characters in the string. But, with that limitation, it's not clear what you actually want or care about. Heck, we could just return a random number and be done with the info you've given us about requirements. — jfriend00, Feb 20 '17 at 17:07
I'm actually making a algorithm to get a crime coefficient from a user name. — Anonymous Group, Feb 20 '17 at 17:10
**DO YOU MEAN RANDOM?** Randomly get a number between 1 and 500 that only contains 1 - 3 digits? — ibrahim mahrir, Feb 20 '17 at 17:10

P1ratRuleZZZ · Accepted Answer · 2017-02-20T17:23:30.703

0

Ok, you can use JS function to get charCode of letter

let str = "some string example";
let sum = 0;
for (let i=0; i<str.length; i++) {
  sum += parseInt(str[i].charCodeAt(0), 10); // Sum all codes
}

// Now we have some value as Number in sum, lets convert it to 0..1 value to scale to needed value
let rangedSum = parseFloat('0.' + String(sum)); // Looks dirty but works
let resultValue = Math.round(rangedSum * 500) + 1; // Same alogorythm as using Math.random(Math.round() * (max-min)) + min;

I hope it helps.

So as you are using nodejs, you can use crypto library to get md5 hash of string and then get it as HEX.

const crypto = require('crypto');
let valueHex = crypto.createHash('md5').update('YOUR STRING HERE').digest('hex');
// then get it as decimal based value
let valueDec = parseInt(valueHex, 16);
// and apply the same algorythm as above to scale it between 1-500

edited Feb 20 '17 at 17:23

answered Feb 20 '17 at 17:16

P1ratRuleZZZ

144
2
7

This works fine, for whatever I've tested till now. Thanks for the help. – Anonymous Group Feb 20 '17 at 17:23
And you need to change `i <= str.length` to `i < str.length` in the for loop – Anonymous Group Feb 20 '17 at 17:23
Oh yes, sorry for that error in loop. Already fixed – P1ratRuleZZZ Feb 20 '17 at 17:25

score 0 · Answer 2 · answered Feb 20 '17 at 17:17

0

function coeficient() {
  return Math.floor(Math.random() * 500) + 1;
}

console.log(coeficient());
console.log(coeficient());
console.log(coeficient());

answered Feb 20 '17 at 17:17

ibrahim mahrir

31,174
5
48
73

THis just generates a random 3 digit number. Thanks but not exactly what I want. @p1ratRulezZZ answer looks promising. – Anonymous Group Feb 20 '17 at 17:25

Algorithm to convert any string to a 1-3 digit number

2 Answers2