An example of using callbacks.
In this first example,
(function() {
var alpha, alphaCallback, beta, betaCallback;
beta = function(callback) {
console.log('gamma');
callback();
}
betaCallback = function() {
console.log('delta');
}
alphaCallback = function() {
console.log('beta');
};
alpha = function(callback) {
console.log('alpha');
callback();
beta(betaCallback);
}
//this is evaluated first
//we pass a reference to the callback
alpha(alphaCallback);
}());
Using callbacks with a setTimeout function — to demonstrate how callbacks are handled asynchronously.
(function() {
var alpha, alphaCallback, beta, betaCallback;
beta = function(callback) {
setTimeout(function() {
console.log('gamma');
}, 1000);
callback();
}
betaCallback = function() {
console.log('delta');
}
alphaCallback = function() {
console.log('beta');
};
alpha = function(callback) {
setTimeout(function() {
console.log('alpha');
}, 1000);
callback();
beta(betaCallback);
}
alpha(alphaCallback);
}());