json.validate - Real Function Reference

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

Arguments

string

required

JSON string to validate. The function reads this argument with string type checking.

DecodeOptions

Optional decode options. A boolean sets useNull. A table can set useNull and maxDepth. maxDepth is clamped from 1 to 4096.

Returns

boolean

true when parsing one complete JSON value succeeds. false when parsing fails inside the protected parse block.

string | nil

Error message on parse failure. The message is prefixed with json.validate and includes a near-position suffix. This return is only present on failure.

number | nil

Parser byte position from the parser on parse failure. This return is only present on failure.

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

Check whether a string contains exactly one complete JSON value.

print(json.validate('{"value":42}'))

local valid, message, position = json.validate('{"value":42 trailing')

if not valid then
    warn(message, position)
end

​Arguments

​Returns

​Types

​DecodeOptions

​Example

Arguments

Returns

Types

DecodeOptions

Example