<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> <script> console.log(Boolean('')); // false console.log(Boolean(0)); // false console.log(Boolean(NaN)); // false console.log(Boolean(null)); // false console.log(Boolean(undefined)); // false console.log(Boolean('123'));//ture console.log(Boolean('hello'));//ture console.log(Boolean('我很好'));//ture </script> </head> <body> </body> </html>
true代表真，false代表假，代表空、否定的值alse），其余全为真（true）
记住以上代码块中的5个假案例即可~
