For this, use hasOwnProperty(). Following is the code −
Example
var markDetails1 ={ 'marks1': 78, 'marks2': 65 }; var markDetails2 ={ 'marks2': 89, 'marks3': 90 } function updateJavaScriptObject(details1, details2) { const outputObject = {}; Object.keys(details1) .forEach(obj => outputObject[obj] = (details2.hasOwnProperty(obj) ? details2[obj] : details1[obj])); return outputObject; } console.log(updateJavaScriptObject(markDetails1, markDetails2));
To run the above program, you need to use the following command −
node fileName.js.
Here, my file name is demo140.js.
Output
This will produce the following output −
PS C:\Users\Amit\JavaScript-code> node demo140.js { marks1: 78, marks2: 89 }