Rust 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. Rust

// 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;
// }

let sb_script = chilkat::StringBuilder::new();
if sb_script.load_file("js_function_array_arg.js", "utf-8").is_err() {
    println!("{}", sb_script.last_error_text());
    return;
}

let js = chilkat::Js::new();

let result = chilkat::JsonObject::new();
result.set_emit_compact(false);

// Call Eval to add the function to the context's global object
if js.eval(&sb_script, &result).is_err() {
    // Examine the result for an exception.
    println!("{}", result.emit().unwrap_or_default());

    // Also examine the LastErrorText.
    println!("{}", js.last_error_text());
    return;
}

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

let func_call = chilkat::JsonObject::new();
func_call.set_emit_compact(false);

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

let _ = func_call.update_string("name", "calculateTotal");

// Create the arguments array.
let args_array = chilkat::JsonArray::new();

// The 1st argument in the arguments array is itself an array.
// Passing -1 indicates to append to the array.
let arg = chilkat::JsonArray::new();
let _ = args_array.add_array_at2(-1, &arg);

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

// Add the "args" array to the funcCall.
let _ = func_call.append_array_copy("args", &args_array);

println!("{}", func_call.emit().unwrap_or_default());

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

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

if js.call_function(&func_call, &result).is_err() {
    // Examine the result for an exception.
    println!("{}", result.emit().unwrap_or_default());

    // Also examine the LastErrorText.
    println!("{}", js.last_error_text());
    return;
}

println!("{}", result.emit().unwrap_or_default());

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

// The function also emitted text to the console.

let sb_out = chilkat::StringBuilder::new();
js.console_output_sb(&sb_out);
println!("{}", sb_out.get_as_string().unwrap_or_default());

// 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:

func_call.clear();
let _ = func_call.update_string("name", "calculateTotal");
let _ = func_call.update_number("args[0][0]", "10.50");
let _ = func_call.update_number("args[0][1]", "20.00");
let _ = func_call.update_number("args[0][2]", "5.25");
println!("{}", func_call.emit().unwrap_or_default());

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;
}