JSFiddle - React, Tailwind, and code Playground
JavaScript
var occupiedTable = '["4,9","1,3"]';
occupiedTable = occupiedTable.slice(1);
occupiedTable = occupiedTable.slice(0, occupiedTable.length - 1);
occupiedTable = occupiedTable.replace(/['"]+/g, '')
occupiedTable = occupiedTable.split(",");
console.log(occupiedTable);