51help TIY
码：
<!DOCTYPE html> <html> <body> <p>假设 y=5，计算 x=y+2果。</p> <button onclick="myFunction()">点击这里</button> <p id="demo"></p> <script> function myFunction() { var y=5; var x=y+2; var demoP=document.getElementById("demo") demoP.innerHTML="x=" + x; } </script> </body> </html>
查看结果: