JSFiddle - React, Tailwind, and code Playground

JavaScript

var myArray=[0, 1, 1, 2, 3, 3, 3];
myArray.sort();

var i=0;
var countArray=[1];
var unique=[myArray[0]];
var outArray=[];
cpt=0;
prevElt=myArray[0];
while (myArray[++i]){
curElt=myArray[i]
if(curElt===prevElt){
    countArray[cpt]=countArray[cpt]+1;
    }
else{
    countArray.push(1);
    unique.push(curElt);
    cpt++;
    }    
prevElt=curElt;    
}
countArray.reverse()

ul=unique.length;

for(i=0;i<ul;i++){
    for(j=0; j< countArray[i];j++){
        outArray.push(unique[i])
        }
}
console.log(outArray)