1. Take the key of the object
Object.keys(obj) returns a string array representing all enumerable properties of a given object
var obj = {
foo: 'bar', baz: 42 };
console.log(Object.keys(obj)); // ['foo', 'baz']
2. Take the value of the object
Method 1: **Object.values(obj)** returns an array of all enumerable property values of a given object itself, the order of the values is the same as the order of using the for...in loop (the difference lies in the for-in loop enumeration Properties in the prototype chain).
var obj = {
foo: 'bar', baz: 42 };
console.log(Object.values(obj)); // ['bar', 42]
console.log(Object.values('foo')); // ['f', 'o', 'o']
Method Two:
let obj = {
a:'aa',
b:'bb',
c:'cc',
d:'dd'
};
for(let i in obj){
console.log(i); //a b c d
console.log(obj[i]); // aa bb cc dd
}
//如果想把值整合在一起，可以var一个数组，然后将值push进数组里
Method three:
var obj = {
foo: 'bar', baz: 42 };
Object.keys(obj).map((key)=>{
console.log(obj[key])});//依次返回 bar 42
3. Take out both the key and value and convert them into an array
Object.entries() returns an array, the member is the key-value pair array of all enumerable properties of the parameter object itself (without inheritance)
var obj = {
foo: 'bar', baz: 42 };
console.log(Object.entries(obj)); // [['foo', 'baz'],['bar',42]]
4. Combine multiple objects into one and remove duplicates
The Object.assign method is used to copy the values of all enumerable properties from one or more source objects to the target object. It will return the target object.
const target = {
a: 1, b: 2 };
const source = {
b: 4, c: 5 };
const returnedTarget = Object.assign(target, source);//{a: 1, b: 4, c: 5}