I bew to the typescript. In my function in the component I try to declare a local variable "contains":
setUpgrade($event) {
contains : Boolean = this.selectedUpgrades.includes($event);
//some logic
}
but on this row:
contains : Boolean = this.selectedUpgrades.includes($event);
on the Boolean I get this error:
Type 'boolean' is not assignable to type 'BooleanConstructor'.
Why I get an error on the variable declaration?
The Boolean type is something that you'd get if you invoked the Boolean constructor:
const somethingWeird = new Boolean(Math.random() < 0.5);
This is almost never what you want - it can behave quite oddly. For example, a Boolean object containing false is truthy. Its typeof is also object, not boolean. Use the boolean type instead.
const contains : boolean = this.selectedUpgrades.includes($event);
Or, even better, leave out the type annotation entirely, and let TS infer it automatically:
const contains = this.selectedUpgrades.includes($event);
That's usually preferable, since it leads to less boilerplate and less code that needs to be read.
Collected from the Internet
Please contact [email protected] to delete if infringement.
Comments