My function has a parameter dtoIn and I am trying to check if it's undefined or null.
I have values assigned like this so it shouldn't be undefined, but I get that the object is undefined anyway. Can I have some advise please.
{
count : 10,
minAge : 10,
maxAge : 10,
}
function main(dtoIn={count, minAge, maxAge}) {
if (typeof dtoIn !== "undefined" && dtoIn !== null){
alert(`empty`);
}
}
I think there are a couple of misunderstandings in your code as to how object destructuring and function default values work.
Consider the following example:
let obj = {
count : 10,
minAge : 10,
maxAge : 10,
}
function main({ count = 15, minAge = 15, maxAge = 15 } = {}) {
console.log(count, minAge, maxAge)
}
main(obj);
main();We don't actually even need to perform any undefined checks here, because this syntax is for either destructuring a given object to count, minAge and maxAge OR if nothing is given, we destructure into count = 15, minAge = 15 and maxAge = 15.
If you want to keep the dtoIn named parameter and have default values for it, you can do that like so:
let obj = {
count : 10,
minAge : 10,
maxAge : 10,
}
function main(dtoIn = { count: 15, minAge: 15, maxAge: 15 }) {
console.log(dtoIn);
}
main(obj);
main();I guess you're assigning function params wrong try this way
let dtoIn = {
count : 10,
minAge : 10,
maxAge : 10,
};
function main(val) {
if (typeof(val) == "undefined" && val !== null){
alert("empty");
}
}
main(dtoIn);