Returns the number of fields in a json object or number of elements in a json array.
[h: len = json.length(jobj)][h: len = json.length(jarr)][h:a=json.fromStrProp("a=1;b=44;c=12")] [json.length(a)]
[h:a=json.fromList("a,1,g,4")][json.length(a)]Returns
3 4