Implement a function clone to copy values from 5 major data types in JavaScript (including number, String, Object, Array, Boolean)

Implement a function clone to replicate values for 5 major data types in JavaScript, including number, String, Object, Array, Boolean.

1 /** Object Cloning2 * Supports basic data types and objects3 * Recursive method*/ 4 functionClone (obj) {5     varo;6     Switch(typeofobj) { 7          Case"Undefined": 8              Break; 9          Case"string": o = obj + ""; Ten              Break;  One          Case"Number": o = obj-0;  A              Break;  -          Case"Boolean": o =obj; -              Break;  the          Case"Object"://object is divided into two cases (objects) or arrays (array) -             if(obj = = =NULL) {  -o =NULL;  -}Else{  +                 if(Object.prototype.toString.call (obj). Slice (8,-1) = = = = "Array") {  -o = [];  +                      for(vari = 0; i < obj.length; i++) {  A O.push (Clone (Obj[i)); at                     }  -}Else{  -o = {};  -                      for(varKinchobj) {  -O[K] =Clone (Obj[k]); -                     }  in                 }  -             }  to              Break;  +         default: o =obj; -              Break;  the     }  *     returno; $ }Panax Notoginseng  - varM1 = Clone ([All]); the varM2 = Clone ({1: ' 1 ', ' Hello ': 32}); +Console.log (M1);//[1, 2, 3] AConsole.log (m2);//{' 1 ': ' 1 ', hello:32}

Expansion: Why use Object.prototype.toString.call (obj) to detect object types? You can refer to this blog post without understanding the function.

Here I mainly explain Object.prototype.toString.call (obj). Slice (8,-1) = = = "Array"? What is the meaning.

Object.prototype.toString.call ([]);  // "[Object array]" [Object array] ". Slice (8,-1);  // "Array"

In the case of an array object, Object.prototype.toString.call ([]) detects the result of "[Object Array]" and intercepts the substring through the slice method. the Slice () method of the string can be used to view the JS elevation P124

Implement a function clone to copy values from 5 major data types in JavaScript (including number, String, Object, Array, Boolean)