C#

Call a JavaScript Function Passing an Array Argument

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Demonstrates how to call a JavaScript function with an argument that is an array. C#

bool success = false;

//  This is the JavaScript function we'll call:

//  function calculateTotal(numbers) {
//    console.log(numbers);
//    let total = 0;
//    
//    // Loop through every number in the array
//    for (const num of numbers) {
//      console.log(num);
//      total += num;
//    }
//    
//    return total;
//  }

Chilkat.StringBuilder sbScript = new Chilkat.StringBuilder();
success = sbScript.LoadFile("js_function_array_arg.js","utf-8");
if (success == false) {
    Debug.WriteLine(sbScript.LastErrorText);
    return;
}

Chilkat.Js js = new Chilkat.Js();

Chilkat.JsonObject result = new Chilkat.JsonObject();
result.EmitCompact = false;

//  Call Eval to add the function to the context's global object
success = js.Eval(sbScript,result);
if (success == false) {
    //  Examine the result for an exception.
    Debug.WriteLine(result.Emit());

    //  Also examine the LastErrorText.
    Debug.WriteLine(js.LastErrorText);
    return;
}

//  ------------------------------------------------------------------------------
//  Call the function calculateTotal(numbers)

Chilkat.JsonObject funcCall = new Chilkat.JsonObject();
funcCall.EmitCompact = false;

//  Create JSON specifying the function name and arguments
//  In this case, there is only 1 argument, and it is an array.

funcCall.UpdateString("name","calculateTotal");

//  Create the arguments array.
Chilkat.JsonArray argsArray = new Chilkat.JsonArray();

//  The 1st argument in the arguments array is itself an array.
//  Passing -1 indicates to append to the array.
Chilkat.JsonArray arg = new Chilkat.JsonArray();
argsArray.AddArrayAt2(-1,arg);

//  Fill in the values for the 1st argument.
arg.AddNumberAt(-1,"10.50");
arg.AddNumberAt(-1,"20.00");
arg.AddNumberAt(-1,"5.25");

//  Add the "args" array to the funcCall.
funcCall.AppendArrayCopy("args",argsArray);

Debug.WriteLine(funcCall.Emit());

//  The funcCall is as follows.  Notice that the 1st (and only) argument is an array.

//  {
//    "name": "calculateTotal",
//    "args": [
//      [
//        10.50,
//        20.00,
//        5.25
//      ]
//    ]
//  }

success = js.CallFunction(funcCall,result);
if (success == false) {
    //  Examine the result for an exception.
    Debug.WriteLine(result.Emit());

    //  Also examine the LastErrorText.
    Debug.WriteLine(js.LastErrorText);
    return;
}

Debug.WriteLine(result.Emit());

//  Result:
//  {
//    "type": "double",
//    "value": 35.75
//  }

//  The function also emitted text to the console.

Chilkat.StringBuilder sbOut = new Chilkat.StringBuilder();
js.ConsoleOutputSb(sbOut);
Debug.WriteLine(sbOut.GetAsString());

//  Output:
//  10.5,20,5.25
//  10.5
//  20
//  5.25

//  -----------------------------------------------------------
//  Note: If the array argument is simple, this is an alternative
//  and simpler way of creating the funcCall:

funcCall.Clear();
funcCall.UpdateString("name","calculateTotal");
funcCall.UpdateNumber("args[0][0]","10.50");
funcCall.UpdateNumber("args[0][1]","20.00");
funcCall.UpdateNumber("args[0][2]","5.25");
Debug.WriteLine(funcCall.Emit());