点击运行
<!DOCTYPE html> <html> <body> <h1>使用 var 声明变量</h1> <p id="demo"></p> <script> var x = 10; // Here x is 10 { var x = 2; // Here x is 2 } // Here x is 2 document.getElementById("demo").innerHTML = x; </script> </body> </html>
运行结果
