JavaScript DateAdd()方法的实现代码

function DateAdd (interval,number,date){ 
    //确保为date类型: 
    date=convertToDate(date); 
    switch(interval.toLowerCase()){ 
        case "y": return new Date(date.setFullYear(date.getFullYear()+number)); 
        case "m": return new Date(date.setMonth(date.getMonth()+number)); 
        case "d": return new Date(date.setDate(date.getDate()+number)); 
        case "w": return new Date(date.setDate(date.getDate()+7*number)); 
        case "h": return new Date(date.setHours(date.getHours()+number)); 
        case "n": return new Date(date.setMinutes(date.getMinutes()+number)); 
        case "s": return new Date(date.setSeconds(date.getSeconds()+number)); 
        case "l": return new Date(date.setMilliseconds(date.getMilliseconds()+number)); 
    } 
}; 
function dateFormat(date){ 
    //确保为date类型: 
    date=convertToDate(date); 
    var defyear = parseInt(date.getFullYear());//當前年 
    var defmonth = parseInt(date.getMonth()+1,10); //當前月 
    var defday=date.getDate();//當前日 
    var result=""; 
    if(defmonth<10&&defday<10){ 
        result=defyear+'-0'+defmonth+'-0'+defday; 
    }else if(defmonth<10){ 
        result=defyear+'-0'+defmonth+'-'+defday; 
    }else if(defday<10){ 
        result=defyear+'-'+defmonth+'-0'+defday; 
    }else{  www.jiaochengji.com
        result=defyear+'-'+defmonth+'-'+defday; 
    } 
    return result; 
}; 
//javascript中定義的replaceAll() 
String.prototype.replaceAll = function(s1,s2){ 
    return this.replace(new RegExp(s1,"gm"),s2); 
}; 
//將日期類型格式的字符串轉化為日期類型: 
function convertToDate(expr){ 
    if(typeof expr=='string'){ 
        expr=expr.replaceAll('-','/');//將字符中的-替換為/,原因是IE或其它瀏覽器不支持-符號的Date.parse() 
        return new Date(Date.parse(expr)); 
    }else{ 
        return expr; 
    } 
};