typescript interface with unknown keys
//credit goes to Andrés Reales interface AllPropertiesString { [key: number]: string; [key: string]: string; } const random: AllPropertiesString = <AllPropertiesString>{}; random[1] = 'This is the value for number 1'; random['1'] = 'This is a string'; console.log(random[1]); // will display 'This is a string' console.log(random["1"]); // will display 'This is a string'