Regex for match a textual file

Question

I must create a regex for match the content of one file but I've one problem. In this file I control that there are, for each line, this instruction:

i=number j=number k=number u=number

But the difficulty is because I must match correctly also

j=number i=number u=number k=number

and any disposition of i,j,k and u. How can I create one regex for all the cases? Note that there can be no any ripetition of i,j,k,u on the same line. Thanks.

Answer 1

(([ijku]=)(?!.*\\\\2)number(?:\\\\s(?=\\\\w)|$)){4} will work for you. This handles repetition case as well.

public static void main(String[] args){
    String s = "i=number j=number k=number u=number";
    System.out.println(s.matches("(([ijku]=)(?!.*\\2)number(?:\\s(?=\\w)|$)){4}"));
    s = "u=number j=number k=number i=number";
    System.out.println(s.matches("(([ijku]=)(?!.*\\2)number(?:\\s(?=\\w)|$)){4}"));
    s = "u=number j=number k=number u=number";
    System.out.println(s.matches("(([ijku]=)(?!.*\\2)number(?:\\s(?=\\w)|$)){4}"));
}

O/P :

true
true
false

Answer 2

您正在寻找的被称为字符类：

[ijku]=number [ijku]=number [ijku]=number [ijku]=number