JSFiddle - React, Tailwind, and code Playground

JavaScript

$(function(){
    var test = {"code_operateur":[""],"cp_cult":["something",""],
        "annee":["2011"],"ca_cult":[""]}

function isEmpty(thingy) {
    return thingy.length == 0;
}

function removeEmpties(thingy) {
    var res = [];
    for(var i in thingy) {
        if(thingy[i]) {
            res.push(thingy[i]);
        }
    }
    return res;
}

for(i in test) {
    if(typeof test[i] == "object") {
        test[i] = removeEmpties(test[i]);
    }
 if ( test[i] == "" || test[i] === null || (typeof test[i] == "object" && isEmpty(removeEmpties(test[i]))) ) {
  delete test[i];
 }
}

for(var i in test) {
    document.write(i+": "+test[i]+"<br>");
}
    });