I have a 2 functions:
const fn1 = (1, 2) => {
//do something
}
const fn2 = ({param1, param2, param3}) => {
$(`#id_one`).text(param1);
$(`#id_two`).text(param2);
param3;
}
Calling functions:
fn2({
param1: 'hello',
param2: 'world',
param3: fn1(1, 2)
});
When I call the function above, fn1() is getting called before fn2(). Why is that happening? I need to go through fn2() before fn1().
() after an identifier that points to a function invokes the function. Since you want to invoke the function after everything in f2 is done, put the ()s inside fn2, not in the caller:
const fn2 = ({param1, param2, param3}) => {
$(`#id_one`).text(param1);
$(`#id_two`).text(param2);
param3();
}
fn2({
param1: 'hello',
param2: 'world',
param3: fn1
});
(): param3(1, 2)
1 and 2, then I'd pass: () => fn1(1, 2) (if they're defined in the caller, but not in the fn2 section)fn2, then use the code in the answer but pass the parameters to param3. If outside fn2, then () => fn1(1,2) as the parameter passed to fn2.You need to pass the callback function into fn2 like this:
fn2({
param1: 'hello',
param2: 'world',
param3: fn1
});
and call fn1 from fn2 like this:
const fn2 = ({param1, param2, param3}) => {
$(`#id_one`).text(param1);
$(`#id_two`).text(param2);
param3();
}
Whenever you use the parentheses, the function is immediately invoked.
What you're currently dong param3: fn1() is saying "param3 is equal to the return value of this function" and it runs fn1() to get the return value, even if the function doesn't return anything.
fn1()has to be resolved in order to assign the property toparam3which is needed in order to create the object, which is passed tofn2. It's all nested. It would perhaps be clearer if you explain why is it a problem thatfn1doesn't need to be called and what you're trying to do in general.