源代码 ：
点击运行
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>开源教程(ossoft.cn)</title> </head> <body> <p>点击按钮创建及增加字符串变量。</p> <button onclick="myFunction()">点击这里</button> <p id="demo"></p> <script> function myFunction() { txt1="What a very"; txt2="nice day"; txt3=txt1+" "+txt2; document.getElementById("demo").innerHTML=txt3; } </script> </body> </html>
运行结果