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());