Dart Requires Chilkat v11.4.0+

Eval JavaScript Returning Int

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Demonstrates getting the completion value of a JavaScript that returns an integer. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example demonstrates getting the completion value of a script,
  // where the last evaluated expression is an integer.

  // The Javascript run in this example is shown below.

  // Load the JavaScript from a file.
  final sbScript = CkStringBuilder();
  try {
    sbScript.loadFile('js_eval_return_int.js', 'utf-8');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final js = CkJs();
  final result = CkJsonObject();

  // Run the JavaScript
  // Eval returns the completion value of the script. This is generally the value of the last evaluated expression.
  // In this case, the last evaluated expression is an int.
  try {
    js.eval(sbScript, result);
  } on ChilkatException {
    print(sbScript.lastErrorText);
    return;
  }

  result.emitCompact = false;
  print(result.emit());

  // Output:

  // {
  //   "type": "int",
  //   "value": 42
  // }
}

JavaScript

const base = 10;
const multiplier = 4;
const offset = 2;

// The last line is a calculation resulting in an integer
// Returns 42.
(base * multiplier) + offset;