JSFiddle - React, Tailwind, and code Playground

JavaScript

function randNum(num){
    var numberToExclude=2;
    var randNumber=Math.floor(Math.random()*(num-1))+1;

    if(randNumber>=numberToExclude) {
        randNumber+=1;
    }
    
    return randNumber;
}

var i,s='';
for(i=0;i<100;i++)
    s += randNum(4) + ' ';

alert(s);