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Square meter, mu, hectare unit conversion applet implemented in javascript_javascript skills
Square meter, mu, hectare unit conversion applet implemented in javascript_javascript skills
Javascript implements square meter, mu, and hectare unit conversion. You can pass parameters through the URL to specify the value of the input box to be the value of any medium unit.
The source code is as follows:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>javascript实现的平方米、亩、公顷单位换算小程序</title>
</head>
<body>
<select onchange="selectChange(this)" id="sel">
<option value="公顷">公顷</option>
<option value="亩">亩</option>
<option value="平方米">平方米</option>
</select>
这个input的值可能是3公顷、3亩、3平方米
<input type="text" value="3" id="input0"/>
<script type="text/javascript">
var a = parseInt('0'); /////这里改为你动态接受到的值，0代表单位为平方米，1为亩，2为公顷
var sel = document.getElementById('sel');
sel.selectedIndex = 2 - a; /////设置单位下拉
var lastUnit = document.getElementById('sel').value; //记录当前单位
var input = document.getElementById("input0");
//10000平米 = 15亩 = 1公顷
var fRate = {//换算率
公顷: { 亩: 15, 平方米: 10000 },
亩: { 平方米: 10000 / 15, 公顷: 1 / 15 },
平方米: { 亩: 15 / 10000, 公顷: 1 / 10000}
};
function selectChange(obj) {//单位改变，执行换算
var v = parseFloat(input.value);//得到原来的值
//执行换算，注意fRate的取值，得到上一次的单位节点，再取当前单位的换算率
var rst = (v * fRate[lastUnit][sel.value]).toFixed(4);//保留4位小数
input.value = rst;
lastUnit = sel.value;//更新当前单位变量
}
</script>
</body>
</html>
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