JavaScript function with default options

Content

Use Object.assign to merge objects.

const original = {     'a': 1,     'b': 2,     'c': 0, };   const updates = {     'c': 3,     'd': 4, };   const result = Object.assign(original, updates); console.log('result:', result); result: { a: 1, b: 2, c: 3, d: 4 }

Create a function that has default options by using Object.assign.

function doThing(options) {     var defaults = {         'debug': false,         'retryCount': 0,     };     options = Object.assign(defaults, options);     console.log(options); } doThing(); // { debug: false, retryCount: 0 }   doThing({'debug': false, 'retryCount': 1}); // { debug: false, retryCount: 1 }   doThing({'debug': true, 'retryCount': 5}); // { debug: true, retryCount: 5 }