js常用函数封装

common

function randomColor(){
var R = randomInt(0,255);
var G = randomInt(0,255);
var B = randomInt(0,255);
return "rgb("+R+","+G+","+B+")";
}

function randomInt(min, max){
return Math.floor(Math.random()*(max-min)) + min;
}

function textNodefilter(nodelist){
var temp = [];
for(var i=0; i<nodelist.length; i++){
    if(nodelist[i].nodeType == 1){
        temp.push(nodelist[i]);
    }
}
return temp;
}

function getStyle(ele){
if(ele.currentStyle) {
    return ele.currentStyle;
} else {
    return getComputedStyle(ele);
} 
}

function toArray(arr){
var a = [];
for(var i = 0; i<arr.length; i++){
    a.push(arr[i]);
}
return a;
}

function log(){
if(console && console.log){
    console.log(arguments);
} else {
    alert(arguments);
}
}

//计算一个dom元素的PageX/Y
function getPagePosition(target){
var sumLeft = target.offsetLeft;
var sumTop = target.offsetTop;
while(target.offsetParent != null){
    sumLeft += target.offsetParent.offsetLeft;
    sumTop += target.offsetParent.offsetTop;
    
    target = target.offsetParent;
 }
return {
    pageX : sumLeft,
    pageY : sumTop
};
}

//封装事件监听的添加
function addEventHandler(ele, eventType, fn, isCapture){
if(ele.addEventListener) {
    ele.addEventListener(eventType, fn, isCapture);
} else {
    ele.attachEvent("on"+eventType, fn);
}
}

//限定一个数字的大小范围
function section(val, min, max) {
return Math.max(min, Math.min(max, val));
}

function hide(ele) {
ele.style.display = "none";
}
function show(ele) {
ele.style.display = "block";
}

(function(){
if(!document.getElementsByClassName){
    document.getElementsByClassName = function(classname){
        var allEle = document.getElementsByTagName("*");
        var temp = [];
        for(var i=0; i<allEle.length; i++){
            if( allEle[i].className.indexOf(classname) != -1){
                temp.push( allEle[i] );
            }
        }
        return temp;
    }
}
})();

dateUtile(现在经常使用moment.sjs)

//判断某年份是否为闰年
function isLeapYear(year){
    return year%4==0 && year%100!=0 || year%400==0;
}


//将日期格式化输出 “2015-08-24”
function date2string(date, sep){
    var sep = sep || "-";
    
    var m = date.getMonth()+1;
    var d = date.getDate();
    return date.getFullYear()+sep+ (m<10?"0"+m:m) + sep+ (d<10?"0"+d:d);
}

date2string(new Date())

//获得某个月份的天数
function getDaysByMonth(month, year){
    year = year || new Date().getFullYear();
    
    if(!month || typeof month != "number" ) {
        console.error("参数必须为数字类型！");
        return;
    } 
    if( !(month > 0 && month < 13) ){
        console.error("月份必须在1-12之间");
        return;
    }
    month = Math.round(month);
    
    switch(month) {
        case 1 : 
        case 3 :
        case 5 :
        case 7 :
        case 8 :
        case 10 :
        case 12 : return 31;
        case 2 : return (isLeapYear(year) ? 29 : 28);
        case 4 :
        case 6 :
        case 9 :
        case 11 : return 30;
    }
}


//将字符串转换为日期
function string2Date(datestr, sep){
    
    if( !sep || !(datestr && datestr.length >= 8) ){
        console.error("字符串格式错误！不能解析");
        return;
    }
    
    var list = datestr.split(sep);
    if( !(list[0].length==4 && list[1]>0&&list[1]<13 && list[2]>0 && list[2]<32) ){
        console.error("字符串格式错误！不能解析");
        return;
    }
    return new Date(datestr);
}


//判断两个日期相差的天数
function getDaysBetweenMonths(d1, d2){
    if( !(d1 instanceof Date && d2 instanceof Date) ){
        console.error("参数传错了！重来！");
        return;
    }
    var dis = Math.abs(d1.getTime() - d2.getTime());
    return (dis/1000/3600/24).toFixed(2);
}


//获得N天以后的日期(string/date)
function getAfterDay(n){
    var now = new Date();
    now.setDate( now.getDate()+n );
    return date2string(now);
}