let fruit = 'apple'; let bag = { [fruit + 'Computers']: 5 // bag.appleComputers = 5 }; #equivelant to let fruit = "apple" let bag = {}; // take property name from the fruit variable bag[fruit + 'Computers'] = 5; // apple = 5 ***** let propVariableName = 'nominalName' // expression const data = { a: 1, [propVariableName]: 2 // assign nominalName as computed property } // use value of expression's computed property data.nominalName // #-> 2 ****** let propVariableNames = [ {'nominalName1: 1'}, {'nominalName2': 2}, {'nominalName3': 3}] // iterate propVariableNames let data = { } data[propVariableName]: propVariableName.getValue()