There is plenty of reference information cJobject on this site, starting with How to use cJobject, or just enter cJobject in the search box. Here’s a quick reminder of what you’ll need to understand to follow this app example.
What is cJobject
It’s an attempt to emulate a JavaScript object within the limits of VBA syntax. It’s fully recursive, so you can have endless parents and children depth, can handle arrays, and knows how to Parse JSON, and how to create it. I use it in almost everything I do in VBA – The great thing for me is to be able to ‘create classes on the fly’ with dynamic properties, which is exactly what we need to be able to parameterize VBA applications.
As a reminder here’s a cJobject slide primer
Some examples
Here’s how it looks against the equivalent JavaScript using a few common things you need to do. Since we are creating classes on the fly at run time, the syntax of VBA makes it a little more wordy, but it achieves approximately the same thing. There are a few useful things exposed also that don’t exist in javaScript
| what | vba | JavaScript |
| Create an object from a JSON string | set job = JSONParse(jsonString) | var job = JSON.parse(jsonString); |
| Create a JSON string from an object | JSONStringify (job) or job.stringify() | JSON.stringify(jsonString); |
| Create a new object (using Nothing as the argument makes this the root) | set job = new cJobject job.init (Nothing) | var job = {}; |
| Access the key of an object (for example the word ‘name’ of the object job.name) | s = job.key | n/a |
| Access the full key of an object (for example the word ‘boss.name’ of the object job.boss.name) | s = job.fullKey | n/a |
| Access the child of an object | set j = job.child(“name”) | j = job.name; |
| Access the value of a child | v = job.child(“age”).value | v = job.age; |
| Access the string value of a child | v = job.child(“age”).toString | v = job.age.toString(); |
| Access the value of an object | v = j.value | v = j |
| Access multiple values deep | v = job.child(“name.first”).value or v = job.child(“name”).child(“first”).value | v=job.name.first |
| Iterate through the children of an object | for each j in job.children | for (var k in job) |
| Find out how many children an object has | n = job.children.count | var n = 0; for (var k in job) { n++ ;} |
| Find the parent object | set j = job.parent | n/a |
| Find an object with a particular key somewhere in a branch | set j = job.find (“child.first”) | n/a |
| Add a new object as a child | job .add “someKey” | job.someKey = {}; |
| Add a new object and give it a value | job.add “someNumber”,”someValue” | job.someNumber = someValue; |
| Set an object to a value | j.value = 100 | j = 100; |
| Add an array | job.add(“someArray”).addArray | job.someArray = []; |
| Add a new member value to an array | job.child(“someArray”).add(,200) | job.someArray.push(200); |
| Add a new object to an array | job.child(“someArray”).add(“newObject”) | job.someArray.push({someObject:null}); |
| iterate through an array | for each j in a.children | for (var i=0; i <a.length;i++) { a[i];} |
| check if an object exists | if not job.childExists(“someKey”) is nothing | if (job.hasOwnProperty(“someKey”)) |
| check to see if im part of an array | if job.isArrayMember | n/a |
| find the topmost object of this tree | set root = job.root | n/a |
| Access my index number in an array | n = job.childIndex | n/a |
| Access the 1st element of an array | a.children(1) | a[0] |
| The length of an array | a.children.count | a.length |
| check to see if im an array | if a.isArrayRoot | if (Array.isArray(a)) |
Complete list of cJobject methods and properties
For more on this see. Data driven VBA apps with JSON