abel sanchez, abel@mit.edu, and john williams, jrw@mit.edu
A callback is a function that is passed as an argument to other code. The receiving code is expected to call back (execute) the argument when needed.
var list = [5,8,9,2,7,6,3,1,4];
function callback(list){
// --- Your Code ---
}
function filter(list,callback){
// --- Your Code ---
}
var filtered = filter(list, callback);
Applying a filter creates a new array with all elements that pass your function. The method takes a callback function.
var numbers = [56, 23, 99, 12, 49, 31];
function callback(){
// --- Your Code ---
}
numbers.filter(callback)
The forEach() method executes a provided function, a callback, once for each array element.
function logArrayElements(element, index, array) {
// --- Your Code ----
}
// log array contents
[2, 7, 5, 3].forEach(logArrayElements);