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finally 语句不论之前的 try 和 catch 中是否产生异常都会执行该代码块。 实例 function myFunction() { var message, x; message = document.getElementById("p01"); message.innerHTML = ""; x = document.getElementById("demo").value; try { if(x == "") throw "值是空的"; if(isNaN(x)) throw "值不是一个数字"; x = Number(x); if(x > 10) throw "太大"; if(x < 5) throw "太小"; } catch(err) { message.innerHTML = "错误: " + err + "."; } finally { document.getElementById("demo").value = ""; } } 完整代码 <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>小白教程网 2d5.net</title> </head> <body> <p>不管输入是否正确,输入框都会再输入后清空。</p> <p>请输入 5 ~ 10 之间的数字:</p> <input id="demo" type="text"> <button type="button" onclick="myFunction()">点我</button> <p id="p01"></p> <script> function myFunction() { var message, x; message = document.getElementById("p01"); message.innerHTML = ""; x = document.getElementById("demo").value; try { if(x == "") throw "值是空的"; if(isNaN(x)) throw "值不是一个数字"; x = Number(x); if(x > 10) throw "太大"; if(x < 5) throw "太小"; } catch(err) { message.innerHTML = "错误: " + err + "."; } finally { document.getElementById("demo").value = ""; } } </script> </body> </html> 效果图 |
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