In this lesson we'll see how Ramda'spathandpathOrfunctions can be used to safely access a deeply nested property from an object while avoiding the dreaded checks forundefinedat each new property in the desired path.
const R = require('ramda'); const {path, pathOr} = R; const acctDept = { name: 'Accounts Payable', location: '14th floor', personnel: { manager: { fName: 'Bill', lName: 'Lumberg', title: 'director of stuff and things', salary: 75000 } } }; const itDept = { name: 'IT', location: 'remote', personnel: {} }; // path: will return undefined if cannot find prop const getMrgLastName = path(['personnel', 'manager', 'lName']); const getMrgLastNameOrDefaultVal = pathOr('Nobody', ['personnel', 'manager', 'lName']) const res = getMrgLastName(acctDept); console.log("res:", res); // Lumberg const res2 = getMrgLastName(itDept); const res3 = getMrgLastNameOrDefaultVal(itDept); console.log("res2:", res2); // undefined console.log("res3:", res3); // Nobody
