how = How.ID in selenium

As per the JavaDocs of Annotation Type FindBy both the expression :

@FindBy(id = "foobar") WebElement foobar;

and

@FindBy(how = How.ID, using = "foobar") WebElement foobar;

Both of the expressions points to the same element.

Modifier How

How is defined in org.openqa.selenium.support.How, extends java.lang.Enum<How> and also implements java.lang.Comparable<How>.The Enum Constants of How are as follows :

• CLASS_NAME
• CSS
• ID
• ID_OR_NAME
• LINK_TEXT
• NAME
• PARTIAL_LINK_TEXT
• TAG_NAME
• UNSET
• XPATH

Update

As per the counter question, if you have a look at the source code of the enum How it is defined as :

public enum How {  CLASS_NAME {    @Override    public By buildBy(String value) {      return By.className(value);    }  },  CSS {    @Override    public By buildBy(String value) {      return By.cssSelector(value);    }  },  ID {    @Override    public By buildBy(String value) {      return By.id(value);    }  },  ID_OR_NAME {    @Override    public By buildBy(String value) {      return new ByIdOrName(value);    }  },  LINK_TEXT {    @Override    public By buildBy(String value) {      return By.linkText(value);    }  },  NAME {    @Override    public By buildBy(String value) {      return By.name(value);    }  },  PARTIAL_LINK_TEXT {    @Override    public By buildBy(String value) {      return By.partialLinkText(value);    }  },  TAG_NAME {    @Override    public By buildBy(String value) {      return By.tagName(value);    }  },  XPATH {    @Override    public By buildBy(String value) {      return By.xpath(value);    }  },  UNSET {    @Override    public By buildBy(String value) {      return ID.buildBy(value);    }  };  public abstract By buildBy(String value);}

So for example when you implement How in conjunction with ID as per the following line :

@FindBy(how = How.ID, using = "foobar") WebElement foobar;

how = How.ID functionally returns By.id(value) and is equivalent to what exactly the following line returns :

@FindBy(id = "foobar") WebElement foobar;

Hence we can conclude that @FindBy(id = "foobar") and @FindBy(how = How.ID, using = "foobar") are just 2 different way to achieve the same result and are available as per user's choice.