kk Blog —— 通用基础

<!-- autocomplete="off" 确保表单已关闭自动填充功能： -->
<form autocomplete="off" action="/index.php">
	<div class="autocomplete" style="width:300px;">
		<input id="myInput" type="text" name="s" placeholder="请输入搜索内容">
	</div>
	<input type="submit">
</form>

.autocomplete {
	/*容器定位设置为 relative:*/
	position: relative;
	display: inline-block;
}
.autocomplete-items {
	position: absolute;
	border: 1px solid #d4d4d4;
	border-bottom: none;
	border-top: none;
	z-index: 99;
	/*设置自动填充项宽度与容器相同*/
	top: 100%;
	left: 0;
	right: 0;
}
.autocomplete-items div {
	font-size: 15px;
	padding: 1px;
	cursor: pointer;
	background-color: #fff;
	border-bottom: 1px solid #d4d4d4;
}
.autocomplete-items div:hover {
	/*鼠标移动到填充项设置的背景颜色*/
	background-color: #e9e9e9;
}
.autocomplete-active {
	/*使用箭头键浏览填充项时的背景颜色*/
	background-color: DodgerBlue !important;
	color: #ffffff;
}

function autocomplete(inp, arr) {
	/*自动填充函数有两个参数，input 输入框元素和自动填充的数组*/
	var currentFocus;
	/* 监听 input 输入框，当在 input 输入框元素中时执行以下函数*/
	inp.addEventListener("input", function(e) {
		var a, b, i, val = this.value, an = 0;
		/*关闭已打开的自动填充列表*/
		closeAllLists();

		if (!val) { return false;}

		currentFocus = -1;
		/*创建 DIV 元素用于放置自动填充列表的值*/
		a = document.createElement("DIV");
		a.setAttribute("id", this.id + "autocomplete-list");
		a.setAttribute("class", "autocomplete-items");
		/*DIV 作为自动填充容器的子元素*/
		this.parentNode.appendChild(a);
		/*循环数组*/
		for (i = 0; i < arr.length; i++) {
			/*检查填充项是否有与文本字段值相同的内容，不区分大小写*/
			if (arr[i].substr(0, val.length).toUpperCase() == val.toUpperCase()) {
				/*为每个匹配元素创建一个 DIV 元素 */
				b = document.createElement("DIV");
				/*匹配项加粗*/
				b.innerHTML = "<strong>" + arr[i].substr(0, val.length) + "</strong>";
				b.innerHTML += arr[i].substr(val.length);
				/*选中的填充项插入到隐藏 input 输入字段，用于保存当前选中值*/
				b.innerHTML += "<input type='hidden' value='" + arr[i] + "'>";
				/*当有人点击填充项（DIV 元素）时执行函数*/
				b.addEventListener("click", function(e) {
					/*选中的填充项插入到隐藏 input 搜索字段*/
					inp.value = this.getElementsByTagName("input")[0].value;
					/*关闭自动填充列表*/
					closeAllLists();
				});
				a.appendChild(b);
				an ++;
				if (an > 20)
					break;
			}
		}
	});

	/*按下键盘上的一个键时执行函数*/
	inp.addEventListener("keydown", function(e) {
		var x = document.getElementById(this.id + "autocomplete-list");
		if (x) x = x.getElementsByTagName("div");
		if (e.keyCode == 40) {
			/*如果按下箭头向下键，currentFocus 变量加 1，即向下移动一位*/
			currentFocus++;
			/*使当前选中项更醒目*/
			addActive(x);
		} else if (e.keyCode == 38) { //up
			/*按下箭头向上键，选中列表项向上移动一位*/
			currentFocus--;
			/*使当前选中项更醒目*/
			addActive(x);
		} else if (e.keyCode == 13) {
			/*如果按下 ENTER 键，阻止提交，你也可以设置 submit 提交*/
			e.preventDefault();

			/* search_word(); */

			if (currentFocus > -1) {
				/*模拟点击选中项*/
				if (x) x[currentFocus].click();
			}
		}
	});

	function addActive(x) {
		/*设置选中的选项函数*/
		if (!x) return false;
		/*移动选项设置不同选中选项的背景颜色*/
		removeActive(x);
		if (currentFocus >= x.length) currentFocus = 0;
		if (currentFocus < 0) currentFocus = (x.length - 1);
		/*添加 "autocomplete-active" 类*/
		x[currentFocus].classList.add("autocomplete-active");
	}
	function removeActive(x) {
		/*移除没有选中选项的 "autocomplete-active" 类*/
		for (var i = 0; i < x.length; i++) {
			x[i].classList.remove("autocomplete-active");
		}
	}
	function closeAllLists(elmnt) {
		/*关闭自动添加列表*/
		var x = document.getElementsByClassName("autocomplete-items");
		for (var i = 0; i < x.length; i++) {
			if (elmnt != x[i] && elmnt != inp) {
				x[i].parentNode.removeChild(x[i]);
			}
		}
	}

	/*点击 HTML 文档任意位置关闭填充列表*/
	document.addEventListener("click", function (e) {
		closeAllLists(e.target);
	});
}

var sites = ["Google","Taobao","Runoob","Wiki","Zhihu","Baidu","Sina","Tmall","JD","Alibaba","QQ","Weixin"];
autocomplete(document.getElementById("myInput"), sites);

function getQueryVariable(variable)
{
	var query = window.location.search.substring(1);
	var vars = query.split("&");
	for (var i=0;i<vars.length;i++) {
		var pair = vars[i].split("=");
		if(pair[0] == variable){return pair[1];}
	}
	return(false);
}

$a = 2586;
$b = 2585.98;
var_dump($a-$b);

期望的结果是：float(0.02)

实际结果：float(0.019999999999982)