Java Requires Chilkat v11.4.0+

Call a JavaScript Function Passing an Array Argument

See more JavaScript Examples

Demonstrates how to call a JavaScript function with an argument that is an array. Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Js;
import com.chilkatsoft.chilkat2.JsonArray;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.StringBuilder;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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;
        // }

        StringBuilder sbScript = new StringBuilder();
        try {
            sbScript.loadFile("js_function_array_arg.js", "utf-8");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Js js = new Js();

        JsonObject result = new JsonObject();
        result.setEmitCompact(false);

        // Call Eval to add the function to the context's global object
        try {
            js.eval(sbScript, result);
        } catch (ChilkatException e) {
            // Examine the result for an exception.
            System.out.println(result.emit());

            // Also examine the LastErrorText.
            System.out.println(e.getLastErrorText());
            return;
        }

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

        JsonObject funcCall = new JsonObject();
        funcCall.setEmitCompact(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.
        JsonArray argsArray = new JsonArray();

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

        System.out.println(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
        //     ]
        //   ]
        // }

        try {
            js.callFunction(funcCall, result);
        } catch (ChilkatException e) {
            // Examine the result for an exception.
            System.out.println(result.emit());

            // Also examine the LastErrorText.
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println(result.emit());

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

        // The function also emitted text to the console.

        StringBuilder sbOut = new StringBuilder();
        js.consoleOutputSb(sbOut);
        System.out.println(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");
        System.out.println(funcCall.emit());
    }
}

JavaScript

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;
}