Javascript-Traversing each and map

Purpose: To obtain the id value of each multi-box;

Each method:

Defines an empty array, and adds the id value to the array through the each method. After the array is converted to a string, alert this value;

 
$ (Function(){VaRArr =[]; $ (": Checkbox"). Each (Function(Index) {arr. Push (This. ID );});VaRSTR = arr. Join (","); Alert (STR );})
 

 

Map Method:

Run return this for each: checkbox. ID; then, the returned values are automatically saved as jquery objects. Then, the get method is used to convert them into Native JavaScript arrays, and then the join method is used to convert them into strings. Finally, the alert value is used;

 
$ (Function(){VaRSTR = $ (": checkbox"). Map (Function(){Return This. ID ;}). Get (). Join (); alert (STR );})
 

 

When an array value is required, it is very convenient to use the map method;