javascript syntax sugar

computed property name syntax: following is the same

var a = “b”; var c = {[a]: “d”}
var a = “b”; var c = {}; c[a] = “d”;

arrow function: shortcut for return object is different

p => { return { foo: ‘bar’ } } //normal
p => ({ foo: ‘bar’ }); //shortcut for return object
p => 10;
p => ‘foo’;
p => true;
p => [1,2,3];
p => null;
p => /^foo$/;

using !! to convert object to boolean