Events and anonymous functions
An anonymous function is a function that is not given a name. In JavaScript, the header is simply function()
without the use of a name.
Why would you want to create a function without a name? Having a name is useful when you are going to use the function repeatedly. If a function is only going to be used once, however, a name isn't really necessary.
We used the following function in the previous example:
window.onload = startFunction;
function startFunction() {
document.getElementById('replacehere').textContent='Replacement text.';
}
Equivalently, we could have used an anonymous function:
window.onload = function() {
document.getElementById('replacehere').textContent='Replacement text.';
}
Anonymous functions have many uses, including for event listeners, which we will consider next.