NativeBase Forex reference

reference:
https://stackoverflow.com/questions/32946793/react-native-textinput-that-only-accepts-numeric-characters
https://flaviocopes.com/how-to-replace-all-occurrences-string-javascript/
https://github.com/GeekyAnts/react-native-easy-grid
https://facebook.github.io/react-native/docs/modal
https://stackoverflow.com/questions/49155960/react-native-nativebase-onchangetext-event-for-searchbar
https://stackoverflow.com/questions/40630918/react-native-input-component-takes-ony-numeric-values
https://stackoverflow.com/questions/33952093/how-to-allow-only-one-dot-in-regex
https://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_match_regexp
https://stackoverflow.com/questions/35764782/identify-return-key-action-in-react-native