Specific implementation of obtaining non-duplicate values ​​​​in 3 arrays_javascript skills

Copy code The code is as follows:

var a = [ "a" , "b" , "c" ],
b = [ "b" , "c" , "d" ],
c = [ "c" , "d" , "e" ],
_a = a.concat( b ).concat( c ),
_hash = {},
_new = [];
for( var i = _a.length; i--; ){
if( !_hash[ _a [ i ] ] ){
_hash[ _a[ i ] ] = 1;
_new.push( _a[ i ] );
};
};
return _new;

Idea: First use concat to splice arrays, and then use an object and a new array (used to store non-duplicate arrays).

Traverse the old array and put the values ​​into the object. If the values ​​are different, they will be put into the new array. If they are repeated, they will not be placed.