majorVersion property Null safety
Major version number (leftmost number) of this browser.
For example, for Chrome 5.0.376.86 beta, this field should be set to 5. An asterisk () may be used to target any version number, and a question mark (?) may be used to target cases where the version number cannot be identified. For example, Chrome . targets any version of Chrome: 1.2, 2.5, 3.5, and so on. Chrome 3. targets Chrome 3.1, 3.5, but not 4.0. Firefox ?.? targets cases where the ad server knows the browser is Firefox but can't tell which version it is.