Lianja

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. Lianja

llSuccess = .F.

//  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;
//  }

loSbScript = createobject("CkStringBuilder")
llSuccess = loSbScript.LoadFile("js_function_array_arg.js","utf-8")
if (llSuccess = .F.) then
    ? loSbScript.LastErrorText
    release loSbScript
    return
endif

loJs = createobject("CkJs")

loResult = createobject("CkJsonObject")
loResult.EmitCompact = .F.

//  Call Eval to add the function to the context's global object
llSuccess = loJs.Eval(loSbScript,loResult)
if (llSuccess = .F.) then
    //  Examine the result for an exception.
    ? loResult.Emit()

    //  Also examine the LastErrorText.
    ? loJs.LastErrorText
    release loSbScript
    release loJs
    release loResult
    return
endif

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

loFuncCall = createobject("CkJsonObject")
loFuncCall.EmitCompact = .F.

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

loFuncCall.UpdateString("name","calculateTotal")

//  Create the arguments array.
loArgsArray = createobject("CkJsonArray")

//  The 1st argument in the arguments array is itself an array.
//  Passing -1 indicates to append to the array.
loArg = createobject("CkJsonArray")
loArgsArray.AddArrayAt2(-1,loArg)

//  Fill in the values for the 1st argument.
loArg.AddNumberAt(-1,"10.50")
loArg.AddNumberAt(-1,"20.00")
loArg.AddNumberAt(-1,"5.25")

//  Add the "args" array to the funcCall.
loFuncCall.AppendArrayCopy("args",loArgsArray)

? loFuncCall.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
//      ]
//    ]
//  }

llSuccess = loJs.CallFunction(loFuncCall,loResult)
if (llSuccess = .F.) then
    //  Examine the result for an exception.
    ? loResult.Emit()

    //  Also examine the LastErrorText.
    ? loJs.LastErrorText
    release loSbScript
    release loJs
    release loResult
    release loFuncCall
    release loArgsArray
    release loArg
    return
endif

? loResult.Emit()

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

//  The function also emitted text to the console.

loSbOut = createobject("CkStringBuilder")
loJs.ConsoleOutputSb(loSbOut)
? loSbOut.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:

loFuncCall.Clear()
loFuncCall.UpdateString("name","calculateTotal")
loFuncCall.UpdateNumber("args[0][0]","10.50")
loFuncCall.UpdateNumber("args[0][1]","20.00")
loFuncCall.UpdateNumber("args[0][2]","5.25")
? loFuncCall.Emit()


release loSbScript
release loJs
release loResult
release loFuncCall
release loArgsArray
release loArg
release loSbOut

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;
}