Passing a Function with Parameters as a Parameter

Passing a function with parameters as a parameter?

Use a "closure":

$(edit_link).click(function(){ return changeViewMode(myvar); });

This creates an anonymous temporary function wrapper that knows about the parameter and passes it to the actual callback implementation.

Pass a JavaScript function as parameter

You just need to remove the parenthesis:

addContact(entityId, refreshContactList);

This then passes the function without executing it first.

Here is an example:

function addContact(id, refreshCallback) {
    refreshCallback();
    // You can also pass arguments if you need to
    // refreshCallback(id);
}

function refreshContactList() {
    alert('Hello World');
}

addContact(1, refreshContactList);

Javascript - add parameters to a function passed as a parameter

Some workaround is possible

function one() {
  var args = Array.prototype.slice.call(arguments);  var func = args[0];  args.splice(0, 1);  args.push(5);  func.apply(this, args);}
function two(arg1, arg2) {  console.log(arg1);  console.log(arg2);}
one(two, 3)

Passing a function pointer with it's own parameters in C

Parameters are not passed. It is arguments that are passed.

So this function declaration

void runner(void (* function)(int in)){
  (*function)(in); 
}

has only one parameter: a pointer to a function, But if you want to call the pointed function that expects an argument then you need to supply an argument.

In this declaration of a function pointer

void (* function)(int in)

the function parameter in has the function prototype scope..

You may declare the function parameter without its identifier like

void (* function)(int)

So you have to declare the function with two parameters like

void runner(void (* function)(int), int in ){
  function(in); 
}

Pay attention to that to dereference the pointer to function is redundant.

All these calls as for example

( *function )( int );

or

( *****function )( in );

are equivalent to

function( in );

How do you pass a function as a parameter in C?

Declaration

A prototype for a function which takes a function parameter looks like the following:

void func ( void (*f)(int) );

This states that the parameter f will be a pointer to a function which has a void return type and which takes a single int parameter. The following function (print) is an example of a function which could be passed to func as a parameter because it is the proper type:

void print ( int x ) {
  printf("%d\n", x);
}

Function Call

When calling a function with a function parameter, the value passed must be a pointer to a function. Use the function's name (without parentheses) for this:

func(print);

would call func, passing the print function to it.

Function Body

As with any parameter, func can now use the parameter's name in the function body to access the value of the parameter. Let's say that func will apply the function it is passed to the numbers 0-4. Consider, first, what the loop would look like to call print directly:

for ( int ctr = 0 ; ctr < 5 ; ctr++ ) {
  print(ctr);
}

Since func's parameter declaration says that f is the name for a pointer to the desired function, we recall first that if f is a pointer then *f is the thing that f points to (i.e. the function print in this case). As a result, just replace every occurrence of print in the loop above with *f:

void func ( void (*f)(int) ) {
  for ( int ctr = 0 ; ctr < 5 ; ctr++ ) {
    (*f)(ctr);
  }
}

Source

Passing a Function (with parameters) as a parameter?

It sounds like you want a Func<T>:

T GetCachedValue<T>(string key, Func<T> method) {
     T value;
     if(!cache.TryGetValue(key, out value)) {
         value = method();
         cache[key] = value;
     }
     return value;
}

The caller can then wrap this in many ways; for simple functions:

int i = GetCachedValue("Foo", GetNextValue);
...
int GetNextValue() {...}

or where arguments are involved, a closure:

var bar = ...
int i = GetCachedValue("Foo", () => GetNextValue(bar));

Python: passing a function with parameters as parameter

Why not do:

big(lite, (1, 2, 3))

?

Then you can do:

def big(func, args):
    func(*args)

Passing functions with arguments to another function in Python?

Do you mean this?

def perform(fun, *args):
    fun(*args)

def action1(args):
    # something

def action2(args):
    # something

perform(action1)
perform(action2, p)
perform(action3, p, r)

---

Related Topics