Check if string is complete (contains all alphabets)

A string is said to be complete if it contains all the characters from a to z. Given a string, check if it complete or not. e.g.

Sample Input

3
wyyga
qwertyuioplkjhgfdsazxcvbnm
ejuxggfsts

Sample Output

NO
YES
NO

Solution using for loop and indexOf()

I wrote a quick function which is able to find this complete string.

package com.howtodoinjava.examples;    public class CheckAllAlphabetsAlgorithms {     public static void main(String[] args)     {         System.out.println( checkAllChars( "qwertyuioplkjhgfdsAzxcvbnm" ) );         System.out.println( checkAllChars( "123" ) );         System.out.println( checkAllChars( "ejuxggfsts" ) );         System.out.println( checkAllChars( "wyyga" ) );     }            private static String checkAllChars ( String input )     {         //If input length is less than 26 then it can never be complete         if(input.length() < 26)         {             return "FALSE";         }                            for (char ch = 'A'; ch <= 'Z'; ch++)         {             if (input.indexOf(ch) < 0 && input.indexOf((char) (ch + 32)) < 0)             {                 return "FALSE";             }         }         return "TRUE";     } }

Output:

TRUE
FALSE
FALSE
FALSE

Solution using for regular expressions

Here is a (ugly because I don’t like long regex) solution to find complete string using regex.

package com.howtodoinjava.examples;    public class CheckAllAlphabetsAlgorithms {     public static void main(String[] args)     {         System.out.println( checkAllCharsUsingRegex( "qwertyuioplkjhgfdsAzxcvbnm" ) );         System.out.println( checkAllCharsUsingRegex( "123" ) );         System.out.println( checkAllCharsUsingRegex( "ejuxggfsts" ) );         System.out.println( checkAllCharsUsingRegex( "wyyga" ) );     }            private static String checkAllCharsUsingRegex ( String input )     {         //If input length is less than 26 then it can never be complete         if(input.length() < 26)         {             return "FALSE";         }                    String regex = "(?i)(?=.*a)(?=.*b)(?=.*c)(?=.*d)(?=.*e)(?=.*f)"                 + "(?=.*g)(?=.*h)(?=.*i)(?=.*j)(?=.*k)(?=.*l)(?=.*m)(?=.*n)"                 + "(?=.*o)(?=.*p)(?=.*q)(?=.*r)(?=.*s)(?=.*t)(?=.*u)(?=.*v)"                 + "(?=.*w)(?=.*x)(?=.*y)(?=.*z).*";                            if(input.matches(regex)){             return "TRUE";         }         return "FALSE";     } }

Output:

TRUE
FALSE
FALSE
FALSE