<!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=utf-8" /> <title>用typeof查看数据类型</title> <style> pre{color:green;padding:10px 15px;background:#f0f0f0;border:1px dotted #333;font:12px/1.5 Courier New;} span{color:#999;} </style> </head> <body> <pre> <script type="text/javascript"> alert(typeof 12345); <span>//输出number</span> alert(typeof "abc"); <span>//输出string</span> alert(typeof document); <span>//输出object</span> </script> </pre> <script> alert("typeof 12345 → " + typeof 12345 + " typeof "abc" → " + typeof "abc" + " typeof document → " + typeof document ); </script> </body> </html>
用parseInt解析数字，并求和
<!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=utf-8" /> <title>用parseInt解析数字，并求和</title> <style> body{font:12px/1.5 arial;text-align:center;} .f-text{50px;border:1px solid #ccc;background:#f0f0f0;font-family:inherit;padding:3px;} span{color:green;padding-right:10px;font-weight:700;} strong{padding:0 10px;} </style> <script type="text/javascript"> window.onload = function () { var aInput = document.getElementsByTagName("input"); var aSpan = document.getElementsByTagName("span")[0]; var i = 0; for (i = 0; i < aInput.length - 1; i++) { aInput[i].onkeyup = function () { this.value = this.value.replace(/[^d]/,"") } } aInput[2].onclick = function () { (aInput[0].value == "" || aInput[1].value == "") ? alert("请输入数字！") : aSpan.innerHTML = parseInt(aInput[0].value) + parseInt(aInput[1].value); } }; </script> </head> <body> <input type="text" class="f-text" /><strong>+</strong><input type="text" class="f-text" /><strong>=</strong><span>?</span><input type="button" value="求和" /> </body> </html>