Several clone methods in Javascript

I. In JavaScript, if the cloned object is of the basic type, we can assign a value directly:

 
1 VaRSSTR = "kingwell";2 VaRCSTR =SSTR;3Alert (CSTR );//Output kingwell4SSTR = "ABC";5Alert (CSTR );//Output kingwell;
 

When a value is assigned to another variable, when the value of that variable changes, the other value will not be affected.

2. If it is not a basic type, it will be all different:

1 VaRRepeated r = [,];2 VaRM =Repeated RR;3Alert (m );//Output 1, 2, 34Repeated r = [,];5Alert (m );//Output 3, 2,; the value is changed, because M is only a reference of R. If the value of R is changed, M will also change accordingly.
 

If we want to clone an array, the simplest method is as follows:

1 VaRRepeated r = [,];2 VaRM = mirror R. Slice (0);3Repeated r = [,];4Alert (m );//Output 0, 1, 2, and 3. Although the value in reverse R has changed, a new array has been created by using the slice method.
 

We can create a function to clone all objects:

 1   Function  Clone (OBJ ){  2       VaR  O;  3      If ( Typeof OBJ = "object" ){  4           If (OBJ = Null  ){  5 O = Null  ;  6 } Else  {  7               If (OBJInstanceof  Array ){  8 O = [];  9                   For ( VaR I = 0, Len = obj. length; I <Len; I ++ ){  10   O. Push (clone (OBJ [I]);  11   }  12 } Else {  13 O = {};  14                   For ( VaR J In  OBJ ){  15 O [J] = Clone (OBJ [J]);  16   }  17   }  18  }  19 } Else  {  20 O = OBJ;  21   }  22       Return  O;  23 }

Iii. node cloning:

  1   var  P = document. getelementsbytagname ("p") [0 ];   2   var  CP = P. clonenode (); ///   clone a p node   3   var  CP = P. clonenode (true); ///   clone a p node, in-depth cloning: Clone the node and its sub-content.