Ty：创建页面，内容为“{{LSL Header|ml=*}}{{LSLC|Keywords}}{{LSLC|Flow Control}}{{LSLC|}} {{函数详情 |函数名 = Function: string llJsonValueType( string json, list specifiers ); |…”

2020-08-20T13:44:17Z

创建页面，内容为“{{LSL Header|ml=*}}{{LSLC|Keywords}}{{LSLC|Flow Control}}{{LSLC|}} {{函数详情 |函数名 = Function: string llJsonValueType( string json, list specifiers ); |…”

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{{LSL Header|ml=*}}{{LSLC|Keywords}}{{LSLC|Flow Control}}{{LSLC|}}

{{函数详情
|函数名 = Function: string llJsonValueType( string json, list specifiers );
|参数= 参数：
string json – A string serialization of a json object.
list specifiers – A path to a value in the json parameter.
|返回值= 返回值：在 json 中返回指定值的类型的字符串。

|注意事项=无

|示例=
示例一
<pre>
//all these functions are untested functions that may have some very strange cases were they acd badly or where the comments are wrong
//see them as buggy PSEUDO-code and consider yourself lucky if there are less than 2 wrong counters and 4 bad pointers/names.
//they are more an example and a concept and unlikely fully functional AS IS.

string JisN(string j){if(llJsonValueType(j,[])==JSON_NUMBER )return llJsonGetValue(j,[]);return "";}
//return the JSON if "j" is a JSON_NUMBER, like j="10.1234" j="-0.1234" j="3.14159" j="-1" j="123456" otherwise return "";
//these would be sting representations of a float because j is a string.
//storing floats in a JSON will easily lose you a lot of accuracy. Integers stored in JSON may have a smaller range than 32-bit signed integers.

string JisA(string j){if(llJsonValueType(j,[])==JSON_ARRAY )return llJsonGetValue(j,[]);return "";}
//return the JSON if "j" is a JSON_ARRAY, like j="[]" j="[1,2]" j="[[1],[3,4]]" otherwise return "";
//these would be string representations of a (nested) list because j is a string.

string JisS(string j){if(llJsonValueType(j,[])==JSON_STRING )return llJsonGetValue(j,[]);return "";}
//return the string that is stored in "j" if "j" is a JSON_STRING, like j="\"PI\"" j="\"3.14\"" j="\"-1\"" otherwise return "";
//these would be string representations of a string, typecast with \" as that within itself,
//because j is a string that is also able to store numbers and floats and (nested) lists ... as strings.
//this returns the string within "j" if "j" is "A string within a string".

/*the above functions return strings to be used in simple
if(JisN(j)){}
if(JisA(j)){}
if(JisS(j)){}
//conditions as if they are booleans. //the boolean-ish condition works because "" equals FALSE within LSL.
The functions MAY return a JSON_STRING or JSON_ARRAY can be useful recursively as shown below:
*/

JstringPARSED(string j){
//j="\"PI\"";
//j="\"3.14\"";
//j="\"-1\"";
string JayWeHaveToGoDeeperS = JisS(JisS(j));
llOwnerSay( JayWeHaveToGoDeeperS ); // says "PI", or "" , or "" , because "3.14" is a JSON_NUMBER and "-1" is a JSON_NUMBER but not a JSON_STRING
string JayWeHaveToGoDeeperN = JisN(JisS(j));
llOwnerSay( JayWeHaveToGoDeeperN ); // says "" , or "3.14000" , or "-1.0000", because "PI" is a JSON_STRING but "PI" is not a JSON_NUMBER

if (llJsonValueType(j,[])==JSON_INVALID){}//would be TRUE for j="";
}

//==== End of JstringPARSED(j) ===== start of Jnested(j) for nested/recursive lists =====

Jnested(string j,list rope){//goes trough each value of a nested JSON_ARRAY and says its value and its "position-list"
//j="[]";
//j="[[1],[2]]";
//j="[-1,[2]]";
//j="[[1],-2]";
//j="[[-3,-4]]"; //the only true case HERE for = JisA(JisA(j)); below
string JayWeHaveToGoDeeperA = JisA(JisA(j));

string subJ=JisA(j);
if (subJ){
//here you actually have to loop trough each entry of the subJ JSON_LIST to test its TYPE for each entry (if we want to go deeper recursively)
//You can go deeper once you know if entry number x is a JSON_LIST (NESTED!!!) or JSON_STRING (for some reason)
//first see how many list entries there are; we go trough entries of subJ starting on the left until its a JSON_INVALID
list types;
integer i = -1;
while (++i != -1){
string type=llJsonValueType(j,[i]);//stores the TYPE of "j"'s entry at position i as "type"
if (type==JSON_INVALID) i=-2; //this exits this the while-loop
else types += [type]; // the list "types" will store all the JSON types, until the first invalid one is reached. (which which should also be for "out of bounds"
}

//this is split in 2 loops to explain 1 task by splitting it in 2 smaller tasks. Actually the loops above and below could be merged easily.

i=llGetListLength(types);//we now have a list that lists all JSON types of j; lets see how long it is;
//and we loop trough all types, calling THIS function recursively if the list contains another nested list in it at position i
while (i--){//I like to go reverse from right to left when ever possible, its faster (??) and costs less memory in LSL (??)
if (llList2String(types,i)==JSON_ARRAY || llList2String(types,i)==JSON_OBJECT){
Jnested(llJsonGetValue(j,[i]));//the function calls itself here, recursively to go trough the nested JSON_ARRAY or JSON_OBJECT
}
else{
llOwnerSay("["+llList2CSV(rope)+"]== "+llJsonGetValue(j,[i]));
//read from your list what json type is at this position and do something with it.
}}}}
//Jnested(json,[]);//would print each value of the nexted JSN_ARRAY with its "address list", that is building up recursively as "rope" that leads you trough the tree/maze.

//Jnested(j) should be useful to read from large matrices (as in 300x300 fields) that may even contain complex numbers at some places.
//I tried to read very long JSONs with llGetSubString(), but llGetSubString() too easily stack-heap collides on very long strings,
//so you have to go trough the nested list using Jnested(j) to read and print it per entry.
</pre>

|相关函数=
[[llList2Json]]
[[llJson2List]]
[[llJsonSetValue]]
[[llJsonGetValue]]
|相关事件=无

}}

LlJsonValueType - 版本历史

Ty：创建页面，内容为“{{LSL Header|ml=*}}{{LSLC|Keywords}}{{LSLC|Flow Control}}{{LSLC|}} {{函数详情 |函数名 = Function: string llJsonValueType( string json, list specifiers ); |…”