web前端常用的封装方法

摘要：放大镜页面加载完毕后执行亲没有数据哦动态添加标签加载地址后传入输出一个函数在上面则定义好这个函数接受一个就是资源类型循环输出可先查看数据点击一次，从多少开始获取获取指定区间范围随机数，包括和如获

        //页面加载完毕后执行
        window.onload = function () {

            var oDemo = document.getElementById("demo");
            var oMark = document.getElementById("mark");
            var FloatBox = document.getElementById("float-box");
            var SmallBox = document.getElementById("small-box");
            var bigBox = document.getElementById("big-box");
            var bigImg = bigBox.getElementsByTagName("img")[0];

            oMark.onmouseover = function (){
                FloatBox.style.display = "block";
                bigBox.style.display = "block";
            }

            oMark.onmouseout = function (){
                FloatBox.style.display = "none";
                bigBox.style.display = "none";
            }

            oMark.onmousemove = function (ev){

                var ev = ev || window.event;
                var left = ev.clientX - oDemo.offsetLeft - SmallBox.offsetLeft - FloatBox.offsetWidth / 2;
                var top = ev.clientY - oDemo.offsetTop - SmallBox.offsetTop - FloatBox.offsetHeight / 2;

                if(left < 10){

                    left = 0;

                }else if(left >= oMark.offsetWidth - FloatBox.offsetWidth - 10){

                    left = oMark.offsetWidth - FloatBox.offsetWidth;

                }

                if(top < 10){

                    top = 0;

                }else if(top >= oMark.offsetHeight - FloatBox.offsetHeight - 10){

                    top = oMark.offsetHeight - FloatBox.offsetHeight;

                }

                FloatBox.style.left = left + "px";
                FloatBox.style.top = top + "px";

                var scaleX = left / (oMark.offsetWidth - FloatBox.offsetWidth);
                var scaleY = top / (oMark.offsetHeight - FloatBox.offsetHeight);

                bigImg.style.left = -scaleX * (bigImg.offsetWidth - bigBox.offsetWidth) + "px";
                bigImg.style.top = -scaleY * (bigImg.offsetHeight - bigBox.offsetHeight) + "px";

            }

        }
        

        function fn1(data){
            var html = "";
            var oUl = document.getElementsByTagName("ul")[0];

            console.log(data);

            if(data.total != -1){
                for(var i=0; i "+ data.books[i].author_intro +"
"+ data.books[i].summary +"
 
" + data.books[i].publisher + "
";
    
                }
    
                oUl.innerHTML = html;
            
            }else{
                document.body.innerHTML+="
亲~~ 没有数据哦~~~
";
            }
            
        }
    
    window.onload = function (){
        
        var oBtn = document.getElementById("btn");
        var iNow = 0;
        oBtn.onclick = function (){
            //动态添加 script 标签   加载URL地址 后传入 callback=fn1 输出一个函数, 在上面则定义好这个函数, 接受一个data 就是资源  json类型,循环输出, 可先console.log(dara) 查看数据
            var oScript = document.createElement("script");
            
            oScript.src="https://api.douban.com/v2/book/search?q=%E6%A0%A1%E5%9B%AD&count=10&start="+ iNow +"&callback=fn1";
            document.head.appendChild(oScript);
            
            // 点击一次+10，从多少开始获取
            iNow += 10;
        
        }
            
    }

function randomFrom(lowerValue,upperValue)
{
    return Math.floor(Math.random() * (upperValue - lowerValue + 1) + lowerValue);
}
//如获取1-100之间的随机数
console.log(randomFrom(1,100));

1、快速排序
    
    /** 
     *   得到中间那位那位数,然后循环判断, arr[i] < 中间数 则push leftArr, 否则push rightArr, 最后返回 left数组 "拼接" 中间数 + right数组 
     */
    function sort(arr){
    
        if(arr.length <= 1){
            return arr;
        }
    
        var numIndex = Math.floor(arr.length/2);
        var numVal = arr.splice(numIndex,1);
        var leftArr = [];
        var rightArr = [];
    
        for(var i=0; i
5、数组去重
1、indexOf 去重

/**
 *   当arr的第一次出现的位置 == i  则是第一次出现就push到tempArr
 */
function unique(arr){

    if (arr.length <= 1){
        return arr;
    }

    var tempArr = [];

    for(var i=0; i
6、深度拷贝
/** 
 *     深度拷贝
 *     使用for in 在循环赋值，避免对象引用
 */
function copy(obj){

    if(typeof obj != "object"){
        return obj;
    }

    var newObj = {};

    for(var attr in obj){

        newObj[attr] = copy(obj[attr]);

    }

    return newObj;

}