String() toString() +””

    1. <!DOCTYPE html>
    2. <html lang="en">
    3. <head>
    4.     <meta charset="UTF-8">
    5.     <meta name="viewport" content="width=device-width, initial-scale=1.0">
    6.     <title>Document</title>
    7. </head>
    8. <body>
    9.     <script>
    10.         // String()   toString()  +""
    11.         var a = true;
    12.         console.log(typeof a.toString())
    13.     </script>
    14. </body>
    15. </html>