How to add a new key value pair in existing JSON object using JavaScript?

1.Add New Property using dot(.)

jsObj.workbookInformation.NewPropertyName ="Value of New Property"; 

2.Add New Property specifying index like in an arrays .

jsObj["workbookInformation"]["NewPropertyName"] ="Value of New Property"; 

Finally

 json = JSON.stringify(jsObj);
 console.log(json)

較複雜的使用方法:

Object.keys(json).map(
  function(object){
    json[object]["newKey"]='newValue';
});

經測試, 外面那層, 好像不用寫, 可以直接使用: json[object][“newKey”]=’newValue’