The handler.deleteProperty()
method is a trap for the
delete
operator.
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Syntax
const p = new Proxy(target, {
deleteProperty: function(target, property) {
}
});
Parameters
The following parameters are passed to the deleteProperty()
method.
this
is bound to the handler.
target
- The target object.
property
- The name or
Symbol
of the property to delete.
Return value
The deleteProperty()
method must return a Boolean
indicating
whether or not the property has been successfully deleted.
Description
The handler.deleteProperty()
method is a trap for the
delete
operator.
Interceptions
This trap can intercept these operations:
- Property deletion:
delete proxy[foo]
anddelete proxy.foo
Reflect.deleteProperty()
Invariants
If the following invariants are violated, the proxy will throw a
TypeError
:
- A property cannot be deleted, if it exists as a non-configurable own property of the target object.
Examples
Trapping the delete operator
The following code traps the delete
operator.
const p = new Proxy({}, {
deleteProperty: function(target, prop) {
if (prop in target){
delete target[prop]
console.log('property removed: ' + prop)
return true
}
else {
console.log('property not found: ' + prop)
return false
}
}
})
let result
p.a = 10
console.log('a' in p) // true
result = delete p.a // "property removed: a"
console.log(result) // true
console.log('a' in p) // false
result = delete p.a // "property not found: a"
console.log(result) // false
Specifications
Browser compatibility
BCD tables only load in the browser
See also
Proxy
handler
delete
operatorReflect.deleteProperty()