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TwitterdeleteKey
Delete an "expando" key value.
map.deleteKey(key)
Deletes a key that was added to an instance, but not pre-defined by the type.
import {DefineMap, Reflect} from "can";
const map = new DefineMap( {propA: "valueA"} );
console.log( map.propA ); //-> "valueA"
map.deleteKey("propA");
console.log( map.propA ); //-> undefined
Parameters
- key
{String}:A string of the key being deleted.
Use
If deleteKey is called on a pre-defined type it sets the value to undefined. This is to keep the setters and getters on all instances of that Type.
import {DefineMap, Reflect} from "can";
const Type = DefineMap.extend(
{seal: false},
{
propA: "string"
}
);
const map = new Type( {propA: "valueA"} );
map.set("propB","valueB");
map.deleteKey("propB"); // This works.
map.deleteKey("propA"); // This doesn't delete the key, but does set the key to undefined.
console.log( Reflect.getOwnKeys(map) ); //-> ["propA"]
console.log( map.propA ); //-> undefined