java - Regex to check for all letters in the alphabet -

i'm brushing on coding skills , working through easy problems i've found online. particular task input txt file contains number of lines, , have program check each line , return "true" or "false" depending on whether line contains 26 letters of alphabet. feel i'm finished, regular expression match string [a-z] returns false no matter do. i've tried changing string lowercase, removing spaces, , nothing seems work.

here's link project well.

the text have in text file "the quick brown fox jumps on lazy dog."

package easy139;   import java.io.filereader; import java.io.ioexception; import java.util.scanner; import java.util.regex.pattern; import java.util.regex.matcher;   public class easy139 {      public static void main(string[] args) {         try {             scanner in = new scanner(new filereader("input.txt"));             while (in.hasnextline()) {                 string line = in.nextline();                 system.out.println(line);                 string nospaces = line.replaceall(" ","");                 if (nospaces.matches("[a-z]")) {                     system.out.println("true");                 }                 else {                     system.out.println("false");                 }             }             in.close();         } catch (ioexception e) {         }     } } 

your test returning false because regex [a-z] means "exactly 1 letter".

a regex works string.matches() is:

(?i)(?=.*a)(?=.*b)(?=.*c)...(?=.*z).* 

this uses 1 ahead each letter, each of asserts letter present. (?i) switch turns on case insensitivity.