child #14942
I have read check documentation: https://checkstyle.org/checks/coding/explicitinitialization.html
I have downloaded the latest checkstyle from: https://checkstyle.org/cmdline.html#Download_and_Run
I have executed the cli and showed it below, as cli describes the problem better than 1,000 words

public class Test {
    int x = 0; // violation,  (default value for its type). 
    int _ = 0; // compile error, unnamed field is not allowed
}

Unnamed variables and unnamed patterns is not applicable to explicit initialization