Array and object copy of ES6

Just remember es6 Array of 、 Object Copy

let srcArray=[{
    key:'value'},'b','c']

• Array copy

let [...cloneArray]=srcArray
 perhaps 
let cloneArray2=[...srcArray]

Above is a light copy , If the elements of the array are objects , Their elements point to the same object , That is to say, modify it casually srcArray[0].key Will affect cloneArray and cloneArray2 Of [0].key Value — Because they point to the same object .

• use Object.assign Implement deep copy
  It can only achieve one layer of depth ！ On the basis of the above shallow copy, determine whether each element is an object , If so, create a new object to replace it ：

for (var i=0;i<cloneArray.length;i++){
    
      if (typeof cloneArray[i]=='object'){
    
           cloneArray[i]=Object.assign({
    },cloneArray[i])
      }
}

stay chrome Run the above script on the console ,cloneArray[0] and srcArray[0] It is already two independent objects , change cloneArray[0] The properties of will not affect srcArray[0]

• use JSON Realize real trial copy
  let clone2=JSON.parse(JSON.stringify(srcArray))
  clone2 It will be a completely new object