Built in ColdFusion Functions as First Class Citizens

The ColdFusion built-in functions will be treated as ‘first-class’ functions so that any built-in function can be passed as an argument.

For instance, this is valid:

function convertCaseForArray(array array, function convertor)
    for (var i=1; i <= arrayLen(array); i++) {
        array[i] = convertor(array[i]);
    return array;

// lCase built-in function is being passed as callback.
resultantArray = convertCaseForArray(['One', 'Two','Three'], lCase);


Now, you can treat the built-in CFML functions like uCase() as objects, being able to assign them to variables, and pass them as arguments.

Another example, this is where lCase and uCase are being returned from a function" (NOTE: This example only works with CF11-CF2021.)

function convertArray(array array, string caseTo) {
    caseConverterFunction = getConvertFunction(caseTo);
    for (var i=1; i <= arrayLen(array); i++) {
        array[i] = caseConverterFunction(array[i]);
    return array;

function getConvertFunction(string caseType) {
    if (caseType == 'lower') return lCase;
    return uCase;

results = {
    "lower" = convertArray(['One', 'Two', 'Three'], 'lower'),
    "upper" = convertArray(['One', 'Two', 'Three'], 'upper')


_lower array: one, two, three _upper array: ONE, TWO, THREE

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