How should guard-for-in, be modified when eslint reports an error?

 for (const i in this.keywords) {
        count += this.keywords[i].list.length;
      }
 The body of a for-in should be wrapped in an if statement to filter unwanted properties from the prototype guard-for-in

how should this be modified?

Eslint
Jul.06,2021

using loops to for in objects will include properties inherited through the prototype chain. This behavior may result in unexpected items in the for loop. 

for (key in foo) {
    doSomething(key);
}

Rule details
this rule is designed to prevent unexpected behavior that can occur when a loop is used if for in does not Filter the results in the loop. Therefore, when the for in loop does not use the if statement to Filter its results, it issues a warning.

the following modes are considered a problem: 

/*eslint guard-for-in: 2*/

for (key in foo) {    /*error The body of a for-in should be wrapped in an if statement to filter     unwanted properties from the prototype.*/
    doSomething(key);
}

the following modes are not considered a problem: 

/*eslint guard-for-in: 2*/

for (key in foo) {
    if ({}.hasOwnProperty.call(foo, key)) {
        doSomething(key);
    }
}

Lou Zhu this seems to be traversing the this.keywords array. If the
array traverses, of course, you can also use for-of, to traverse the properties of the object
, but for-in can only be used to traverse the properties of the object, because the array is actually a special object, so it can also access its elements through properties, but such access will bring unexpected problems, so the subject, think about what you want to traverse in the end?
change it to: 

for (i in this.keywords) {
  if(this.keywords.hasOwnProperty(i)){ //, 
    count += this.keywords[i].list.length;
  }
}

A better solution introduction to teacher Ruan Yifeng's ES6 

for (i of this.keywords) {
  count += this.keywords[i].list.length;
}

on the other hand, you can also start with eslint and disable checking, but in fact, this is contrary to using eslint, so I suggest writing code that conforms to eslint rules, forming good habits, and being able to troubleshoot some problems while writing.

Previous: What is the simple principle of LokiJS? How many restrictions can be placed on the number of mobile phones it can use?

Next: A problem about js addition

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1eabfcc-47e55.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1eabfcc-47e55.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?