lookupByPath

The lookupByPath method returns the value at the specified path in the JSON array.

NOTE:

This method does not make a copy of the value, so modifying the returned value affects the original object.

Syntax

lookupByPath( path )

Arguments

Argument Description
path (string) The path of the value to return. Construct the path from array indexes and object attribute names, and use a slash (/) as the separator. If an object attribute name includes a slash, then escape the slash with a backslash, for example "one\\/two". Notice that you must also escape a backslash with another backslash.

Returns

(LuaJsonValue) Returns the value that exists at the specified path, or nil if the specified path does not exist.

Example

local myJsonObject = LuaJsonObject:new()
myJsonObject:assign( {
        attr1=LuaJsonObject:new( { n=42, x=5 } ),
        attr2=LuaJsonArray:new( 1, 2, "three" ),
    } )

local myJsonValue = LuaJsonValue:new( myJsonObject )

print ( myJsonValue:lookupByPath("attr2/2"):value() )
-- three (LuaJsonArrays are zero-indexed)

-- Modifying the returned value changes the original object
local lookup = myJsonValue:lookupByPath("attr1"):object()
lookup:assign("y",3)
print (myJsonValue:string())
-- {"attr1":{"n":42,"x":5,"y":3},"attr2":[1,2,"three"]}

See Also


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