Lua 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. Lua

local chilkat = require("chilkat")

-- 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;
-- }

local sbScript = chilkat.StringBuilder.new()
local success = sbScript:load_file("js_function_array_arg.js", "utf-8")
if not success then
    print(sbScript.last_error_text)
    return
end

local js = chilkat.Js.new()

local result = chilkat.JsonObject.new()
result.emit_compact = false

-- Call Eval to add the function to the context's global object
success = js:eval(sbScript, result)
if not success then
    -- Examine the result for an exception.
    print(result:emit())

    -- Also examine the LastErrorText.
    print(js.last_error_text)
    return
end

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

local funcCall = chilkat.JsonObject.new()
funcCall.emit_compact = false

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

funcCall:update_string("name", "calculateTotal")

-- Create the arguments array.
local argsArray = chilkat.JsonArray.new()

-- The 1st argument in the arguments array is itself an array.
-- Passing -1 indicates to append to the array.
local arg = chilkat.JsonArray.new()
argsArray:add_array_at2(-1, arg)

-- Fill in the values for the 1st argument.
arg:add_number_at(-1, "10.50")
arg:add_number_at(-1, "20.00")
arg:add_number_at(-1, "5.25")

-- Add the "args" array to the funcCall.
funcCall:append_array_copy("args", argsArray)

print(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:call_function(funcCall, result)
if not success then
    -- Examine the result for an exception.
    print(result:emit())

    -- Also examine the LastErrorText.
    print(js.last_error_text)
    return
end

print(result:emit())

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

-- The function also emitted text to the console.

local sbOut = chilkat.StringBuilder.new()
js:console_output_sb(sbOut)
print(sbOut:get_as_string())

-- 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:update_string("name", "calculateTotal")
funcCall:update_number("args[0][0]", "10.50")
funcCall:update_number("args[0][1]", "20.00")
funcCall:update_number("args[0][2]", "5.25")
print(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;
}