so I noticed that when you use .addEventListener() you can get its event array like this:
document.getElementById("elementID").addEventListener("click",function(event) {
console.log(event);
});
Is there any way I can create my own function like this? I tried this before but I completely forgot how I managed to do it.
Right now I am trying
function foo(do) {
let a = 0;
setTimeout(do,1);
return a;
}
foo(function(a) {
console.log(a);
});
(results in undefined)
You can pass extra arguments to setTimeout, but note that updating the value in the function does not propagate it back (also note do is a reserved keyword so I changed the name to fn)
function foo(fn) {
let a = 0;
setTimeout(fn,1,a);
return a;
}
const result = foo(function(a) {
console.log(a);
a += 1
});
console.log(result);So, you can pass an object in instead, and updating that will indeed propagate the change:
function foo(fn) {
let a = {value:0};
//setTimeout(fn,1,a);
fn(a)
return a.value;
}
const result = foo(function(a) {
console.log(a);
a.value += 1
});
console.log(result);But note that I had to take out the setTimeout and replace it with a direct call to fn(a) - if I would have left that in, the function would have returned before the call to fn was made:
function foo(fn) {
let a = {value:0};
setTimeout(fn,1,a);
return a.value;
}
const result = foo(function(a) {
console.log(a);
a.value += 1
});
console.log(result);
Okay I found a solution:
function foo(event) {
setTimeout(function() {
var a = 0;
event(a);
},1);
}
foo(function(a) {
console.log(a);
});
logs 0
I forgot to mention that I am using code.org and coding with code.org is very very weird. It won't let you do a lot of really cool things like adding arguments for the setTimeout
a from inside event, nor return from the setTimeout function.
atodo().doby adding them to the setTimeout call - likesetTimeout(do,1, argument1, argument2, ...);ato be changed infoothoughundefined