tao.js

使用javaScript实现了与MS计算器功能相同的简易计算器!

//给文本框初始值，和确定焦点位置函数
//全局变量
var contextLen = 33;
var taoNum = false;
var PendingOp = "";
var result = 0;
function window.onload()
{
	testForm.textContext.focus();
    document.testForm.textContext.value=0;	
}
//清除函数
function onClear()
{
	testForm.textContext.focus();

	document.testForm.textContext.value='';
}
//(C)函数
function onClearC()
{
	testForm.textContext.focus();

	document.testForm.textContext.value=0;

	PendingOp = "";
	result = 0;
	taoNum = false;
}
//(CE)函数
function onClearCE()
{
	testForm.textContext.focus();

	document.testForm.textContext.value=0;

	PendingOp = "";
	result = 0;
	taoNum = false;
}
//(Backspace)函数
function onBackspace()
{
	if(document.testForm.textContext.value == "0" || document.testForm.textContext.value == "1")
	{
		document.testForm.textContext.value = 0;
	}
	else
	{
		i=0;
		var tao = document.testForm.textContext.value;
		i++;
		if(tao.length <=1 )
		{
			document.testForm.textContext.value = '0';
		}
		else
		{
			document.testForm.textContext.value = tao.substring(0,tao.length - i);
		}
	}
}
//点击数字
function onClickNum(Num)
{
	if (taoNum) 
	{
		document.testForm.textContext.value  = Num;
		taoNum = false;
	}
	else 
	{
		if (document.testForm.textContext.value == "0")
		{
			document.testForm.textContext.value = Num;
		}
		else if(document.testForm.textContext.value == 'null')
		{
			document.testForm.textContext.value = Num;
		}
		else if(document.testForm.textContext.value == 'nul')
		{
			document.testForm.textContext.value = Num;
		}
		else if(document.testForm.textContext.value == 'nu')
		{
			document.testForm.textContext.value = Num;
		}
		else if(document.testForm.textContext.value == 'n')
		{
			document.testForm.textContext.value = Num;
		}
		else
		{
			document.testForm.textContext.value += Num;
		}
	 }
}
//小数点的处理
function onClickType1(Num)
{	
	if( document.testForm.textContext.value == "0")
	{
		document.testForm.textContext.value = "0"+Num
	}
	else
	{
		if(document.testForm.textContext.value.indexOf('.') ==-1)
		{
			document.testForm.textContext.value += Num;
		}
		else
		{
			//不做处理就OK 
		}
	}
}
//操作符的处理(+)
function onClickAccumulate(OpTag)
{
	var context = document.testForm.textContext.value;

	if (taoNum && PendingOp != "=");

	else
	{
		taoNum = true;
		if ( '+' == PendingOp )
		{
			result += parseFloat(context);
		}
		else if ( '-' == PendingOp )
		{
			result -= parseFloat(context);
		}
		else if ( '/' == PendingOp )
		{
			result /= parseFloat(context);
		}
		else if ( '*' == PendingOp )
		{
			result *= parseFloat(context);
		}
		else
		{
			result = parseFloat(context);
		}
		document.testForm.textContext.value = result;
		PendingOp = OpTag;
	}
}
//操作符的处理(+)转换(-)
function onChangeTag()
{
	var tao = document.testForm.textContext.value;

	if(tao.substring(0,1)=='-')
	{
		document.testForm.textContext.value = tao;
	}
	else
	{
		document.testForm.textContext.value = '-' + tao;
	}
}
//操作符的处理(1/x)
function onFenNum()
{
	var tao = document.testForm.textContext.value;

	result = 1 / tao;

	document.testForm.textContext.value = result;
}
//操作符的处理(sqrt)
function onSqrt()
{
	var tao = document.testForm.textContext.value;

	result = Math.sqrt(tao);

	document.testForm.textContext.value = result;
	
}
//操作符的处理(Null)
function onNull()
{
	document.testForm.textContext.value = null;
}