用JS写的简单的计算器实现代码

1.本页效果图片

2.美化后的效果

<！DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html> <head> <script> Array.prototype.remove=function（index） { if（isNaN（index）||index>this.length）{return false;} for（var i=0,n=0;i<this.length;i++） { if（this[i]！=this[index]） { this[n++]=this[i] } } this.length-=1 } function commonMath（）{ //类初始化 this.init = function（）{ this.tmp = ""; this.debug = 0; this.output = ""; this.method = ""; this.sign = 1;//0:-;1:+ this.register = Array（）;//寄存器 } //设置报错信息 this.showmsg = function（msg）{ if（this.debug == 1） alert（msg）; } //设置运算符 this.setMethod = function（_method）{ this.method = _method; _length = this.register.length; if（_length == 0）{ if（this.tmp == ""） return; this.register[0] = this.tmp; this.register[1] = _method; this.tmp = ""; return; } if（_length = 2 || this.tmp == ""）{ this.register[1] = _method; } if（_length == 2 && this.tmp ！= ""）{ this.register[2] = this.tmp; this.run（1）; } if（_length == 3） this.run（1）; } //设置显示值 this.setValue = function（_value）{ var tmp = parseInt（eval（this.tmp+"+""+_value+"""））; max = /^-？d{1,9}$/i; if（ max.test（tmp） == false）{ return; } this.tmp = tmp; this.output.value = this.tmp; } //设置符号 this.setSign = function（）{ var del = 0; var sign = Array（"-","+"）; this.sign = this.sign ^ 1; _sign = sign[this.sign]; if（/d/i.test（this.tmp）== false && this.register.length > 0）{ del = 1; this.tmp = this.register[0]; } if（_sign == "-"）{ this.tmp = -this.tmp; }else{ this.tmp = Math.abs（this.tmp）; } this.output.value = this.tmp; if（del == 1）{ this.register[0] = this.tmp; this.tmp = ""; } } //获取按键 this.getValue = function（input）{ var _in = input; var inputList = document.getElementsByTagName（"input"）; this.output = inputList[0]; regMethod = /^[+|-|*|/]$/i; if（regMethod.test（_in））{ this.setMethod（_in）; return; } regNum = /^d$/i; if（regNum.test（_in））{ this.setValue（_in）; return; } regSign = /^+/-$/i; if（regSign.test（_in））{ this.setSign（_in）; return; } regResult = /^=$/; if（regResult.test（_in））{ this.run（）; return; } } //计算结果 this.run = function（type）{ if（this.register.length < 2） return this.showmsg（1）; if（this.register.length == 2 && （this.tmp == ""）） return this.showmsg（2）; if（this.register.length == 2 && this.tmp ！= ""）{ this.register[2] = this.tmp; this.run（）; } this.showmsg（this.register.join（" "））; var _exp = parseInt（eval（this.register.join（" "）））; this.output.value = _exp; for（i=0;i<3;i++）{ this.register.remove（i）; } this.register[0] = _exp; this.tmp = ""; if（type） this.register[1] = this.method; return; } } var commonMath = new commonMath（）; commonMath.init（）; </script> <style> #main{ width:100%; height:100%; } #inputs{ position:relative; top:50%; left:50%; } .inbutton{ width:30px; } .outbutton{ width:145px; text-align:right; } .tcenter{ text-align:center; } </style> </head> <body> <span class="outbutton tcenter">etongchina@gmail.com</span> <span><input id="output" type="text" class="outbutton" maxlength="9" value="." /></span> <span><input type="button" class="inbutton" value="7" onclick="commonMath.getValue（this.value）" /></span> <span><input type="button" class="inbutton" value="8" onclick="commonMath.getValue（this.value）" /></span> <span><input type="button" class="inbutton" value="9" onclick="commonMath.getValue（this.value）" /></span> <span><input type="button" class="inbutton" value="+" onclick="commonMath.getValue（this.value）" /></span> <span><input type="button" class="inbutton" value="4" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="5" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="6" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="-" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="1" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="2" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="3" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="*" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="0" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="+/-" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="." onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="inbutton" value="/" onclick="commonMath.getValue（this.value）;" /></span> <span><input type="button" class="outbutton tcenter" value="计算" onclick="commonMath.getValue（"="）;" /></span> </body> </html>

[Ctrl+A 全选注:如需引入外部Js需刷新才能执行]