i want to pass a function to another function as a parameter.
I want to do that because the latter function calls an async Jquery method and AFTER that gives a result ba
$('#AddThirdParty').click(function() {
var func = function() { // NOTE: no "new"
alert('1');
alert('2');
alert('3');
}
alert('4');
LoadHtml(func);
alert('5');
});
function LoadHtml(funcToExecute) {
//load some async content
funcToExecute(); // NOTE: parentheses
}
Two errors: the syntax for anonymous functions does not include the keyword new
; and JavaScript requires parentheses for function calls, even if functions do not take any arguments. When you just say funcToExecute
, that is just a variable giving its value in a context where nothing is using that value (kind of like writing 3;
as a statement).
You might notice that you already know how to use anonymous functions: you did not write $('#AddThirdParty').click(new function() ...);
$('#AddThirdParty').click(function() {
var func = new function() {
alert('1');
alert('2');
alert('3');
}
alert('4');
LoadHtml(func);
alert('5');
});
function LoadHtml(funcToExecute) {
//load some async content
funcToExecute;
}
The new
keyword creates an object from the function. This means the function (which is anonymous) gets called immediatly. This would be the same as
var foo = function() {
alert("1");
alert("2");
alert("3");
}
var func = new foo();
This means your creating a new object (not a function!) and inside the constructor your alert 1,2,3. Then you alert 4. Then you call LoadHtml which does nothing, then you alert 5.
As for
funcToExecute;
The funcToExecute is just a variable containing a function. It actually needs to be executed.