JavaScript handler.ownKeys() method in JavaScript is a trap for Reflect.ownKeys() method and this method returns an enumerable object.
Syntax:
const p = new Proxy(target, {
ownKeys: function(target) {
}
});
Parameters: This method accepts a single parameter as mentioned above and described below:
- target: This parameter holds the target object.
Return value: This method always returns an enumerable object.
Below examples illustrate the handler.ownKeys() method in JavaScript:
Example 1: This example returns the keys of the object using the handler.ownKeys() method in JavaScript.
javascript
const monster1 = { prop1: 253, prop2: "Geeks", prop3: 0101011}const handler1 = { ownKeys(target) { return Reflect.ownKeys(target) }}const proxy = new Proxy(monster1, handler1);for (let key of Object.keys(proxy)) { console.log(key);} |
Output:
prop1 prop2 prop3
Example 2: This example returns the keys of the object using the handler.ownKeys() method in JavaScript.
javascript
let proxy1 = new Proxy({}, { ownKeys: function (target) { console.log("handler.ownKeys() Method"); return ['Geeks1', 'Geeks2', 'Geeks3']; }});console.log(Object.getOwnPropertyNames(proxy1)); |
Output:
handler.ownKeys() Method Geeks1,Geeks2,Geeks3
Supported Browsers: The browsers supported by handler.ownKeys() method are listed below:
- Google Chrome 49 and above
- Edge 12 and above
- Firefox 18 and above
- Opera 36 and above
- Safari 10 and above
We have a complete list of Javascript Proxy/handler methods, to check those go through the Javascript Proxy/handler Reference article.
