javascript实现简单的乘法
网友问了个问题,顺便就写出来了,他要求点有三个文本框,第一二个分别是乘数,当点击第三个文本框时出现结果,很简单就写出来.
http://%77%77%77%2E%66网站制作%6F学习网%72%61%73%70%2E%63%6E
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE> 两数相乘得出结果</TITLE></HEAD>
<script language="javascript">
<!--http://%77%77%77%2E%66网站制作%6F学习网%72%61%73%70%2E%63%6E
function checkNum(str)
{return!/\D/.test(str)}
function getback()
{
var num1 = document.getElementById('num1');
if(num1.value==''){alert('乘数1必须存在!');num1.focus();return;}
if(!checkNum(num1.value)){alert('乘数1必须是数字!');num1.focus();return;}
var num2 = document.getElementById('num2');
if(num2.value==''){alert('乘数2必须存在!');num2.focus();return;}
if(!checkNum(num2.value)){alert('乘数2必须是数字!');num2.focus();return;}
var num = document.getElementById('num');
num.value = num1.value * num2.value;
}
-->
</script>
<BODY>
乘数1 :<input type="text" id="num1" name="num1" size="25"><br>
乘数2: <input type="text" id="num2" name="num2" size="25"><br>
结果: <input type="text" id="num" value="" name="num" size="25" onclick="getback();">
</BODY>http://%77%77%77%2E%66网站制作%6F学习网%72%61%73%70%2E%63%6E
</HTML>