JSFiddle - React, Tailwind, and code Playground

JavaScript

var dict = {
    'a': 'aa',
    'b': 'bb'
};

var arr = [];
for (var key in dict) {
    if (dict.hasOwnProperty(key)) {
        arr.push( [ key, dict[key] ] );
    }
}

console.log(JSON.stringify(arr));