# VB6JSON

**Repository Path**: a5k3rn3l/vb6json

## Basic Information

- **Project Name**: VB6JSON
- **Description**: VB6 解析/读写 JSON 的库
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 1
- **Forks**: 2
- **Created**: 2024-07-29
- **Last Updated**: 2026-03-09

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# VB6JSON

JSON parser/exporter for Visual Basic 6.0

## Usage

Copy `modJson.bas` to your project.

Call `ParseJSONString()` function to parse a JSON string, then get a `Variant` which represents the JSON data.
Or optionally there's another sub `ParseJSONString2()` uses a `ByRef` param to retrieve the parsed object, which helps with VB6's `Set` mess.

The returned `Variant` represents the JSON data. During parsing, the library has the following behavior:
 * Numbers turns into `Long` or `Currency` depends on it's range (i.e. If it can't fit into a `Long` then it's a `Currency`).
   - Floating point numbers or numbers with scientific notation will be a `Double`.
 * Strings turns into VB6 Strings.
 * Arrays turn into VB6 Variant Arrays, every element of the array doesn't need to be the same type.
 * Objects turns into `Scripting.Dictionary`.

The function `JSONToString()` do the reverse work: turn the `Variant` into a JSON string.

### Note

Because `Scripting.Dictionary` is a VB object but the others are not, and in VB6, assignments on objects need a `Set` syntax. Still, assignments on non-object variables need not use `Set` syntax, it's recommended not to design functions that return the data from `ParseJSONString()` or `ParseJSONString2()`, but design functions or subs that return data via params, to avoid the mess of `Set` non-`Set` syntax striction.

Use `IsObject()` to check if the `Variant` is an object, use `IsArray()` to check if if the `Variant` is an array.
Use `VarType()` to get the type of `Variant`, if the type is `vbString`, then the `Variant` is a string.
If it's not an object, nor an array, also not a string, then use `IsNumeric()` to check if it's a number.

## Examples

Please see the following examples.

### Example 1

Read a list.

```
Sub Example1()
Dim JsonObj As Variant
ParseJSONString2 " [ 114, 514, ""1919"", 8.10e2 ] ", JsonObj

Debug.Print JsonObj(0); JsonObj(1); JsonObj(2); JsonObj(3)
End Sub
```

### Example 2

Read an object

```
Sub Example2()
Dim JsonObj As Variant
ParseJSONString2 "{""Mike"": 123, ""Mary"": 456, ""Sam"": 789}", JsonObj

Debug.Print "Sam: "; JsonObj("Sam")
Debug.Print "Mike: "; JsonObj("Mike")
Debug.Print "Mary: "; JsonObj("Mary")
End Sub
```

### Example 3

The typical practice of processing JSON data returned from REST API.

```
Sub Example3()
Dim JsonObj As Variant
ParseJSONString2 "{""success"": true, ""data"": {""text"": ""Hello Json!"", ""title"": ""VB6 Json""}}", JsonObj
'''ParseJSONString2 "{""success"": false, ""wording"": ""API failed.""}", JsonObj

If JsonObj("success") = False Then
    MsgBox JsonObj("wording"), vbExclamation, "API failed."
Else
    MsgBox JsonObj("data")("text"), vbInformation, JsonObj("data")("title")
End If
End Sub
```

## References

See [JSON Specification](https://www.json.org/json-en.html)

See [VarType](https://learn.microsoft.com/en-us/office/vba/language/reference/user-interface-help/vartype-function)