I know you can Symbol (), but you can"t new Symbol (), but how do you do that?
or can I write a function that can only be called simply, without new, and report an error as soon as I add new
I know you can Symbol (), but you can"t new Symbol (), but how do you do that?
or can I write a function that can only be called simply, without new, and report an error as soon as I add new
function Foo() {
if (this instanceof Foo) {
throw new Error("new is not permitted.");
}
}
new Foo();Arrow function is
it is hard to say how it is implemented internally. It can also be achieved with pure js:
function Foo() {
if (this !== window) { // nodewindowglobal
throw new Error("new is not permitted.");
}
...
}
new Foo(); // Previous: Supervisor failed to start the process
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