The map () method in JavaScript

map Definitions and methods

The

Map () method returns a new array in which the elements of the array are called after the function is processed by the original array element.  
Map () method processes the elements sequentially, in the order of the original array elements.  
note:  
map does not detect an empty array  
map does not change the original array  
arr.map (function ( Currentvalue,index,arr), Thisvalue)  
parameter description  
function (Currentvalue,index,arr)  
must, function, Each element in the array executes this function function parameter  

currentvalue must be current element value  
index the index value of the current element is optional  
arr optional The array object to which the current element belongs.  
We'll see a little demo, and we'll be at a glance  

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The map () method in JavaScript