How to use Object.keys() and Object.values() methods in js?

In the previous article [How to use the Object.entries() method] we learned that using the entries() method can use the [key, value] pair of the object as an array element, in the form of an array Iterate over the output. So if you just want to traverse a single key value or value value in the [key, value] pair in the form of an array, how can you implement it? This article will introduce to you how to use the Object.keys() method and the Object.values() method to output a single key value or value value in an object [key, value] pair.

Object.keys() method

The Object.keys() method can convert an object as parameters, and then traverse the key values ​​in the [key, value] pair of this object in the form of an array.

Basic syntax:

Object.keys(obj)

Object.values() method

Object The .values() method can take an object as a parameter, and then traverse the value values ​​in the [key, value] pair of this object in the form of an array.

Basic syntax:

Object.values(obj)

Usage of Object.entries() and Object.values() methods

1. List all key attributes or value attributes of the object, for example:

var obj ={ name: '小明', age: '20岁', sex: '男' };
console.log(Object.keys(obj));
console.log(Object.values(obj));

Output:

It can be seen that using Object. The keys() method traverses the key and outputs: name, age, sex; uses the Object.values() method to traverse the value and outputs: Xiao Ming, 20 years old, male.

2. List the key attributes or value attributes specified in the object, for example:

var obj ={ name: '小明', age: '20岁', sex: '男' };
console.log(Object.keys(obj)[0]);
console.log(Object.values(obj)[0]);

Output:

It can be seen that, Specify the key value "name" in the first [key, value] pair of the returned object, and the value value "Xiao Ming" in the first [key, value] pair.

3. Return ordered values ​​based on random key values ​​

var obj ={ 70: 'x', 20: 'y', 35: 'z' };
console.log(Object.keys(obj));
console.log(Object.values(obj));

Output:

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