JSFiddle - React, Tailwind, and code Playground

JavaScript

function shufff(strin,seed){
    strin = strin.split("");
    var tem;
    var j;
    var tt = strin.length;
    for(var i=0; i<tt; i++){
        j = ( seed % (i+1) + i) % tt;
        tem=strin[i];
        strin[i] = strin[j];
        strin[j] = tem;
    }
    return strin.join("");
}

var tom='tomollow';
alert(shufff(tom,6543));
alert(shufff(tom,6550));