<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html;charset=gb2312"> <title>my second javascript file</title> </head> <body> hello,world! <br/> <div style="background:pink;300px;height:400px;"> <from action="" method="" id="form1"> <p> <label for="beforenum">请输入要格式化的数字：</br> <input name="beforenum" type="text" id="beforenum" ></input> </label> </p> <p> <label for="numlength">请输入要格式化的数字的长度：</br> <input name="numlength" type="text" id="numlength" ></input> </label> </p> <p> <label for="afternum">格式化后的数字：</br> <input name="afternum" type="text" id="afternum"></input> </label> </p> <input name="submit" type="button" class="" onClick="formatNo(document.getElementById('beforenum').value, document.getElementById('numlength').value);" value="转换"/> <input name="cancel" type="button" class="" value="取消"/> </form> </div> <script language="javascript"> //输出变量类型 var typea = 3; var typeb = "name"; var typec = null; Objecta = new Object(); document.writeln("<pre>a的类型为" + (typeof typea) + " b的类型为" + (typeof typeb) + " Object1的类型为" + (typeof Objecta) + "</pre>"); //条件运算符 var a = 20; var b = 20; document.writeln(a != b) ? true : false; document.writeln("<pre>我喜欢学习 javascript!!! "); //new运算符 Object1 = new Object(); Array2 = new Array(); Date3 = new Date("May 21 2015") document.writeln(Date3.getFullYear() + "</pre>");//如果是Month必须加1，因为月是从0开始的 //大小写转换 var myString = new String("Xinqing wil be Happy!"); var lower = myString.toLowerCase(); var upper = myString.toUpperCase(); document.writeln("myString转换为大写字母是" + upper); //将数字格式化为指定长度 //在按“转换”按钮时调用函数，带参调用 function formatNo(str1, len1) { if (len1 == "" || str1 == "") { alert("请输入数字和长度"); } alert("长度" + len1 + "；字符" + str1 + ";"); var strLen = str1.length; alert("长度" + len1 + "；字符" + strLen + ";"); str2 = ""; for (i = 0; i < len1; i++) { str2 = str2 + str1.substr(i, 1); } var afternum1 = document.getElementById("afternum"); afternum1.value = str2; } </script> </body> </html>