JSFiddle - React, Tailwind, and code Playground

JavaScript

let donneesSources=[{"toto": "Length","titi":"name"},{"toto": "Length","titi":"Laboum"}]
let monTableau = [];

for(let i = 0; i < donneesSources.length; i++) {
    let cle = donneesSources[i].toto;
    console.log(cle);
    let valeur = donneesSources[i].titi;
    console.log(valeur);
   monTableau[cle] = valeur;
}
console.log(monTableau);