Home > Web Front-end > Front-end Q&A > What are the methods for traversing objects in es6

What are the methods for traversing objects in es6

青灯夜游
Release: 2022-06-08 17:04:41
Original
12624 people have browsed it

6 ways to traverse an object: 1. The "for...in" statement can loop through the object's own and inherited enumerable properties; 2. keys() traverses the property names, values () Traverse the property values; 3. getOwnPropertyNames(), which can return an array containing all properties, etc.

What are the methods for traversing objects in es6

The operating environment of this tutorial: Windows 7 system, ECMAScript version 6, Dell G3 computer.

6 ways to traverse object properties in ES6

1, for...in

Loop through the object's own and inherited enumerable properties (excluding symbol attributes)

for (let k in obj) {}
Copy after login

Loop through the object's own and inherited enumerable properties (loop through the object's own and inherited enumerable properties (excluding Symbol properties)

let obj = {'0':'a','1':'b','2':'c'}
for (let k in obj) {
	console.log(k+':'+obj[k])
}
//0:a
//1:b
//2:c
Copy after login

What are the methods for traversing objects in es6

##2, Object.keys(obj)|| Object.values(obj )

Returns an array, including all enumerable properties of the object itself (excluding inheritance) (excluding Symbol properties)

keys() is the pair of property names The traversal, values() is the traversal of attribute values

let obj = {'0':'a','1':'b','2':'c'}
console.log(Object.keys(obj))
//["0","1","2"]
console.log(Object.values(obj))
//["a","b","c"]
Copy after login

What are the methods for traversing objects in es6

##3, Object.getOwnPropertyNames(obj) Returns an array containing all the properties of the object itself (excluding properties, but including non-enumerable properties)

let obj = {'0':'a','1':'b','2':'c'};

Object.getOwnPropertyNames(obj).forEach(function(key){
    console.log(key,obj[key]);
});
// 0 a
// 1 b
// 2 c
Copy after login

What are the methods for traversing objects in es6

##4. Object .getOwnPropertySymbols(obj)

Returns an array containing all the Symbol properties of the object itself

Example: Get the object's own Symbol value property

var obj = {};
var a = Symbol("a");
var b = Symbol.for("b");

obj[a] = "localSymbol";
obj[b] = "globalSymbol";

var objectSymbols = Object.getOwnPropertySymbols(obj);

console.log(objectSymbols.length); // 2
console.log(objectSymbols)         // [Symbol(a), Symbol(b)]
console.log(objectSymbols[0])      // Symbol(a)
Copy after login

What are the methods for traversing objects in es6

5. Reflect.ownKeys(obj)

Returns an array containing all the properties of the object itself, regardless of the property name It is a Symbol or a string, regardless of whether it is enumerable.

const object1 = {
  property1: 42,
  property2: 13
};

const array1 = [];

console.log(Reflect.ownKeys(object1));
// expected output: Array ["property1", "property2"]

console.log(Reflect.ownKeys(array1));
// expected output: Array ["length"]
Copy after login

What are the methods for traversing objects in es6##6. Reflect.enumerate(obj)

Returns an Iterator object, traversing all the enumerable properties of the object itself and inherited (excluding Symbol properties), the same as the for ... in loop.

var obj = { x: 1, y: 2 };

for (var name of Reflect.enumerate(obj)) {
  console.log(name);
}
// logs "x" and "y"
Copy after login
[Related recommendations:javascript video tutorial

web front-end

The above is the detailed content of What are the methods for traversing objects in es6. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
es6
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template