本文方法超级简单,思路非常的值得推荐,小伙伴们参考下吧
			 
			复制代码代码如下:
			
		<!DOCTYPE html> 
		<html> 
		<head> 
		<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />  
		    <title>javascript 简单计算器</title> 
		    <script> 
		        //定义全局变量         var one="1"; 
		        var two="2"; 
		        var three="3"; 
		        var four="4"; 
		        var five="5"; 
		        var six="6"; 
		        var seven="7"; 
		        var eight="8"; 
		        var nine="9"; 
		        var zero="0"; 
		         var plus="+",minus="-",multiply="*",divide="/",decimal="."; 
		         function enter(obj,string){ 
		                obj.expr.value+=string; 
		            } 
		         function compute(obj){//单击等于"="按钮调用的函数;                  obj.expr.value=eval(obj.expr.value);//用JS得eval()方法计算name为expr中的公式              } 
		  </script> 
		</head> 
		<body> 
		    <form name="calc" id="calc" action="">  
		        <table border="1">  
		        <td colspan="4"><input type="text" name="expr" size="30" action="compute(this.form)" /></td>  
		        <tr>  
		        <td><input type="button" value=" 7 " onclick="enter(this.form,seven)" /></td>  
		        <td><input type="button" value=" 8 " onclick="enter(this.form,eight)" /></td>  
		        <td><input type="button" value=" 9 " onclick="enter(this.form,nine)" /></td>  
		        <td><input type="button" value=" / " onclick="enter(this.form,divide)" /></td>  
		        </tr>  
		        <tr>  
		        <td><input type="button" value=" 4 " onclick="enter(this.form,four)" /></td>  
		        <td><input type="button" value=" 5 " onclick="enter(this.form,five)" /></td>  
		        <td><input type="button" value=" 6 " onclick="enter(this.form,six)" /></td>  
		        <td><input type="button" value=" * " onclick="enter(this.form,multiply)" /></td>  
		        </tr>  
		        <tr>  
		        <td><input type="button" value=" 1 " onclick="enter(this.form,one)" /></td>  
		        <td><input type="button" value=" 2 " onclick="enter(this.form,two)" /></td>  
		        <td><input type="button" value=" 3 " onclick="enter(this.form,three)" /></td>  
		        <td><input type="button" value=" - " onclick="enter(this.form,minus)" /></td>  
		        </tr>  
		        <tr>  
		        <td colspan="2"><input type="button" value=" 0 " onclick="enter(this.form,zero)" /></td>  
		        <td><input type="button" value=" . " onclick="enter(this.form,decimal)" /></td>  
		        <td><input type="button" value=" + " onclick="enter(this.form,plus)" /></td>  
		        </tr>  
		        <tr>  
		        <td colspan="2"><input type="button" value=" = " onclick="compute(this.form)" /></td>  
		        <td colspan="2"><input type="button" value="AC" onclick="form.reset()"/></td>  
		        </tr>  
		        </table>  
		</form>  
		</body> 
		</html>
			 
			是不是超级NB的代码,大神级的!