JSFiddle - React, Tailwind, and code Playground

by slace

JavaScript

function flatten(a){
        var result = [],first;
        while (a.length) {
                first = a.shift();
                if (toString.call(first)=="[object Array]") {
                        a = first.concat(a);
                } else {
                        result.push(first);
                }
        }
        return result;
}
    
var data = [
    [ [1, [4,5]], [2, { foo: ['bar','baz'] }], [3, [6,7,[8],9]] ]
    ];

console.log(flatten(data));