js 实现的计算器

一、HTML

	
		
		
		
		
		
		
		
	
	
		

		
（1）一个JavaScript 计算器
		


		

			

				
			
			

				
				
				
				
				
			
			

				
				
				

				


				
				
				

				


				
				
				

				


				
				
				
			
			

				
				
				
				
			
			

				
				
				
				

				


				
				
				
				
			

		

		

	

二、CSS

body{
	width: 1000px;
	margin: 0 auto;
	padding: 100px 0;
}

/*

	计算器：

 */
#calculator{
	width: 620px;
	margin: 0 auto;
}
#calculator input{
	font-size: 20px;
	padding: 25px;
}
#result{
	width: 560px;
}
#bce input{
	width: 118px;
}
#nums input{
	width: 200px;
}
#operation input{
	width: 150px;
}
#get-result input{
	width: 150px;
}

三、js

$(document).ready(function(){
	load1()
})

var result = ""
var str = ""
function load1(){
	//实现计算器事件监听
	bceIt()
	addIt()
	showResult()
}
function bceIt(){
	$("#backspace").click(function(){
		str = $("#result").val().substr(0, str.length - 1)
		$("#result").val(str)
	})
	$("#CE").click(function(){
		$("#result").val("")
	})
	$("#C").click(function(){
		$("#result").val("")
	})
}
function addIt(){
	var jqs = ["#le", "#ri", "#nums input", "#operation input"]
	for (i in jqs){
		$(jqs[i]).click(function(){
			str = $("#result").val() + $(this).val()
			$("#result").val(str)
		})
	}
}
function showResult(){
	$("#get-result input").click(function(){
		var type = $(this).attr("id")
		try{
			result = eval(str)
		}catch(e){
			alert("请按正确格式输入运算！")
		}
		switch(type){
			case "sin":
				result = Math.sin(result)
				break
			case "cos":
				result = Math.cos(result)
				break
			case "tan":
				result = Math.tan(result)
				break
			case "ln":
				result = Math.log(result)
				break
			case "square":
				result = Math.pow(result, 2)
				break
			case "sqrt":
				result = Math.sqrt(result)
				break
			case "recip":
				result = 1.0 / result
				break
		}
		str = result
		$("#result").val(str)
	})
}