package Ġcom . ali ay n . test . ext enst ion Ċ Ċ import Ġjava . util . regex . Pattern ĊĊ Ċ fun ĠString . is Password Valid (): ĠBoolean Ġ{ ĊĠĠĠ Ġval Ġpassword Pattern Ġ= Ġ"^ (? = .* [ 0 - 9 ]) (? = .* [ a - z ]) (? = .* [ A - Z ]) (? = \\ S +$ ). { 4 , }$ " ĊĠĠĠ Ġval Ġpattern Ġ= ĠPattern . compile ( password Pattern ) ĊĠĠĠ Ġval Ġmatcher Ġ= Ġpattern . matcher ( this ) ĊĠĠĠ Ġreturn Ġmatcher . matches () Ċ }