not stuffing string values in js

Question

I want to randomize user input string using sort() function.. but it's not working properly. Can anybody help me solving this problem?

function getAndSetVal() {
  var txt1 = document.getElementById('txt').value;
  document.getElementById('txt2').value = txt1;
}

// get value
function getVal() {
  var txt = document.getElementById('txt').value;
  alert(txt);
  txt1.sort(function() {
    return .5 - Math.random();
  });
}

<input type="text" id="txt" name="txt" onclick="this.value = '' " />
<button onclick="getAndSetVal();">Get Value</button>
<input type="text" id="txt2" name="txt" onclick="this.value = '' " />

The `sort` comparator function takes 2 arguments, the left and the right item. — Mr. Polywhirl, Mar 18 '20 at 14:19
@Mr.Polywhirl Doesn't it also need to return `-1`, `0`, or `1`? `0.5 - Math.random()` won't do that. — evolutionxbox, Mar 18 '20 at 14:20
@evolutionxbox It doesn't need to be `-1,0,+1`, `<0, =0, >0` will work. — Keith, Mar 18 '20 at 14:25
**Use case explanation is vague and insufficient** (couple of perfectly functional snippets rejected by OP without a clear reason), so voted to close — Yevhen Horbunkov, Mar 18 '20 at 15:03

Kevyn Klava · Answer 1 · 2020-03-18T16:16:34.403

0

String are arrays in some sense but not really, so you have to create an array to use the sort function, try like this:

    function shuffle(){
        document.getElementById('txt2').value = getVal();
    }

    function getVal()
    {
        const txt = document.getElementById('txt').value;
        return txt
            .split(",")
            .map(word => word.trim())
            .sort((a, b) => Math.random() > .5 ? 1 : -1)
            .join(", ");
    }

<input type="text" id="txt" name="txt" value="orange, avocato, banana, fruit" />
<button onclick="shuffle()">Shuffle</button>
<input type="text" id="txt2" name="txt" />

And the sort function pass two parameter and expect return the values 1, -1 or 0.

1 when the first parameter should came first

-1 when the second parameter should came first

0 when doesn't matter the order between both parameters

edited Mar 18 '20 at 16:16

answered Mar 18 '20 at 14:25

Kevyn Klava

316
1
7

@Vicky see if this works for you – Kevyn Klava Mar 18 '20 at 15:26
not working bro.. – Vicky Mar 18 '20 at 15:31
see this code how it's work.. but instead of providing strings in program i want to provide strings from user input – Vicky Mar 18 '20 at 15:33
var fruits = ["Banana", "Orange", "Apple", "Mango"]; fruits.sort(function(){return .5-Math.random();}); document.write(fruits); – Vicky Mar 18 '20 at 15:33
Got it, try this new version. – Kevyn Klava Mar 18 '20 at 16:17
ohh bro Thanks working perfectly now... – Vicky Mar 18 '20 at 16:44

Mr. Polywhirl · Accepted Answer · 2020-03-18T16:43:33.170

0

You need to split the word, sort, and re-join.

If the random number i.e. 0 -> 1 falls in:

the first third, return -1
the last third, return +1
the middle, return 0

Edit: Instead of Math.random() (which is predictable), you can implement a seeded random number generator. David Bau's seedrandom library is light-weight and easy to integrate into your JavaScript application.

Just drop the script in your <head> and instantiate a new random number generator with a seed of the current time in milliseconds.

var random = new Math.seedrandom(new Date().getTime());

function shuffle() {
  document.getElementById('txt2').value = randomSort(document.getElementById('txt').value);
}

function randomSort(value) {
  return value.trim().split(/\s*,\s*/).sort((a, b) => {
    return ((p) => {
      return p < (1/3) ? -1 : p > (2/3) ? +1 : 0;
    })(random()); // Instead of Math.random()
  }).join(', ');
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/seedrandom/3.0.5/seedrandom.min.js"></script>
<input type="text" id="txt" name="txt" value="Banana, Orange, Apple, Mango" />
<button onclick="shuffle()">Shuffle</button>
<input type="text" id="txt2" name="txt" />

edited Mar 18 '20 at 16:43

answered Mar 18 '20 at 14:33

Mr. Polywhirl

42,981
12
84
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var fruits = ["Banana", "Orange", "Apple", "Mango"]; fruits.sort(function(){return .5-Math.random();}); document.write(fruits); – Vicky Mar 18 '20 at 14:37
look at above code how its randomize all strings separately but i just want randomize user input string – Vicky Mar 18 '20 at 14:38
@Vicky how are they inputting the values? – Mr. Polywhirl Mar 18 '20 at 14:56
Shuffling with `sort()` is [slow](https://jsperf.com/array-shuffle-mine/1) and inefficient (try *shuffling* `abcdefg`-string several times - it returns original string after couple of iterations). There's a much faster and *way more random* [shuffling method](https://stackoverflow.com/a/56749849/11299053). I know, you have taken that from OP, but proceeding this way means encouraging OP to go wrong way. – Yevhen Horbunkov Mar 18 '20 at 15:00
ABC, xyz, sunny, funny, pqr ...... like this – Vicky Mar 18 '20 at 15:00
@YevgenGorbunkov I addressed the random issue. – Mr. Polywhirl Mar 18 '20 at 16:43
@Vicky Just split the words by optional white-space (surrounded) commas, sort with a random number, and join the words back into a string. – Mr. Polywhirl Mar 18 '20 at 16:44
thanks for help ... problem solved – Vicky Mar 18 '20 at 16:55
@Vicky I just updated my response, since you did not originally say you were splitting on words. – Mr. Polywhirl Mar 18 '20 at 17:03
@Mr.Polywhirl : *'...I addressed the random issue'* and it is still slow and now unnecessarily overcomplicated – Yevhen Horbunkov Mar 19 '20 at 07:50

not stuffing string values in js

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