json.decodeSafe - Real Function Reference

json.decodeSafe(json: string, options?: DecodeOptions): boolean | any | nil | string | nil | number | nil

Arguments

string

required

JSON text to parse. This argument is checked as a string before parse errors are caught.

DecodeOptions

Optional decode options. A boolean sets useNull directly. A table can set useNull and maxDepth; maxDepth is clamped from 1 to 4096. Invalid option argument types are checked before parse errors are caught.

Returns

boolean

True when parsing succeeds, false when the parser reports an error.

any | nil

Decoded value on success, nil on parse failure. Valid JSON false returns success as true and decoded as false, so check the success return value.

string | nil

Error message on parse failure, otherwise nil. The message includes the json.decodeSafe prefix and parser position.

number | nil

Parser byte position on parse failure, otherwise nil.

Types

DecodeOptions

Controls JSON parsing behavior.

Name	Type	Required	Description
`useNull`	`boolean`	No	Represents JSON null with the library’s null sentinel instead of nil.
`maxDepth`	`integer`	No	Sets the maximum nesting depth, clamped from 1 to 4096.

Example

Parse JSON and use the success return value to separate valid false or nil results from parse failures.

local ok, value = json.decodeSafe("false")

if ok then
    print(value == false)
end

local parsed, _, message, position = json.decodeSafe("{")
if not parsed then
    warn(message, position)
end

​Arguments

​Returns

​Types

​DecodeOptions

​Example

Arguments

Returns

Types

DecodeOptions

Example