javascript 如何使用javascript在数组中找到最早的日期

how to find earliest date in an array using javascript

提问by user3010195

how to find earliest date i.e min date in an array using javascript? Example:I have an array a holding

如何使用javascript在数组中找到最早的日期，即最小日期？示例：我有一个数组

{10-Jan-2013,12-Dec-2013,1-Sep-2013,15-Sep-2013}

My output should be :

我的输出应该是：

{10-Jan-2013,1-Sep-2013,15-Sep-2013,12-Dec-2013}.

How can i do this?

我怎样才能做到这一点？

回答by David says reinstate Monica

I'd suggest passing an anonymous function to the sort()method:

我建议将匿名函数传递给该sort()方法：

var dates = ['10-Jan-2013','12-Dec-2013','1-Sep-2013','15-Sep-2013'],
    orderedDates = dates.sort(function(a,b){
        return Date.parse(a) > Date.parse(b);
    });

console.log(orderedDates); // ["10-Jan-2013", "1-Sep-2013", "15-Sep-2013", "12-Dec-2013"]

var dates = ['10-Jan-2013', '12-Dec-2013', '1-Sep-2013', '15-Sep-2013'],
  orderedDates = dates.sort(function(a, b) {
    return Date.parse(a) > Date.parse(b);
  });

console.log(orderedDates);

JS Fiddle demo.

JS小提琴演示。

Note the use of an array ['10-Jan-2013','12-Dec-2013','1-Sep-2013','15-Sep-2013']of quoted date-strings.

请注意使用带['10-Jan-2013','12-Dec-2013','1-Sep-2013','15-Sep-2013']引号的日期字符串数组。

The above will give you an array of dates, listed from earliest to latest; if you want only the earliest, then use orderedDates[0].

以上将为您提供一系列日期，从最早到最晚列出；如果你只想要最早的，那么使用orderedDates[0].

A revised approach, to show only the earliest date – as requested in the question – is the following:

修改后的方法，只显示最早的日期——如问题所要求的——如下：

var dates = ['10-Jan-2013', '12-Dec-2013', '1-Sep-2013', '15-Sep-2013'],
    earliest = dates.reduce(function (pre, cur) {
        return Date.parse(pre) > Date.parse(cur) ? cur : pre;
    });

console.log(earliest); // 10-Jan-2013

var dates = ['10-Jan-2013', '12-Dec-2013', '1-Sep-2013', '15-Sep-2013'],
  earliest = dates.reduce(function(pre, cur) {
    return Date.parse(pre) > Date.parse(cur) ? cur : pre;
  });

console.log(earliest);

JS Fiddle demo.

JS小提琴演示。

References:

参考：

• Date.parse().
• Array.prototype.reduce().
• Array.prototype.sort().

• Date.parse().
• Array.prototype.reduce().
• Array.prototype.sort().

回答by driangle

Assuming you have an array of Dateobjects.

假设你有一个Date对象数组。

function findEarliestDate(dates){
    if(dates.length == 0) return null;
    var earliestDate = dates[0];
    for(var i = 1; i < dates.length ; i++){
        var currentDate = dates[i];
        if(currentDate < earliestDate){
            earliestDate = currentDate;
        }
    }
    return earliestDate;
}