JSFiddle - React, Tailwind, and code Playground
JavaScript
var res = {"totalSize":3,"done":true,"records":[{"Id":"1","CaseNumber":"1","Subject":"test1"},{"Id":"2","CaseNumber":"2","Subject":"test2"},{"Id":"3","CaseNumber":"3","Subject":"test3"}]}
console.log('res: '+JSON.stringify(res, null, 2))
var extractedRecord = res.records.slice(0, 1);
console.log('extractedRecord: '+JSON.stringify(extractedRecord, null, 2))