ネットで調べても見当たらなかったので作ってみました。
const json = JSON.parse('{"id":"vhUfi3t31goA","string":"root","number":1,"arrayString":["string1","string2"],"arrayNumber":[1,2],"object":{"childId":"boihF33gS3","childString":"child","childNumber":1,"childArrayString":["child_string1","child_string2"],"childArrayNumber":[1,2]}}'); SetNullRecursiveAllProperties(json); function SetNullRecursiveAllProperties(obj) { for (var property in obj) { if (obj.hasOwnProperty(property) && typeof obj[property] === 'object') { SetNullRecursiveAllProperties(obj[property]); } else if (obj.hasOwnProperty(property)) { obj[property] = null; } } } console.log(json); // > Object { id: null, string: null, number: null, arrayString: Array [null, null], arrayNumber: Array [null, null], object: Object { childId: null, childString: null, childNumber: null, childArrayString: Array [null, null], childArrayNumber: Array [null, null] } }