JS 比较日期-优快云博客

本文介绍了一种JavaScript中日期格式化的实用方法，并提供了一个简单的校验输入日期是否合法的示例。通过自定义的Date原型方法实现了日期的格式化输出，同时展示了如何对比输入日期与当前日期来判断其有效性。

Date.prototype.format = function(format) {
var o = {
    "M+" : this.getMonth()+1, //month
    "d+" : this.getDate(),    //day
    "h+" : this.getHours(),   //hour
    "m+" : this.getMinutes(), //minute
    "s+" : this.getSeconds(), //second
    "q+" : Math.floor((this.getMonth()+3)/3), //quarter
    "S" : this.getMilliseconds() //millisecond
}
if(/(y+)/.test(format)) format=format.replace(RegExp.$1,
    (this.getFullYear()+"").substr(4 - RegExp.$1.length));
for(var k in o)if(new RegExp("("+ k +")").test(format))
    format = format.replace(RegExp.$1,
      RegExp.$1.length==1 ? o[k] :
        ("00"+ o[k]).substr((""+ o[k]).length));
return format;
}

// 校验输入日期是否合法
    var nowDate = new Date();
    var createdDateStr = document.getElementById("text_7").value;
    var yearInt = new Number(createdDateStr.substring(0, 4));
    var monthInt = new Number(createdDateStr.substring(5, 7));
    var dayInt = new Number(createdDateStr.substring(8, 10));
    var createdDate = new Date();
    createdDate.setFullYear(yearInt, monthInt - 1, dayInt);

    alert("createdDate:: " + createdDate + "   nowDate:: " + nowDate);

var isCanSubmit = true;
if (createdDate >= nowDate) {
   alert("成立日期不能晚于或等于当前日期！");
   isCanSubmit = false;
}