function getTwoLenNumStr(num) { if (num < 10) return "0" + num; else return num; } window.formatDate = function (millisTime) { var time = new Date(millisTime); return time.getFullYear() + "/" + getTwoLenNumStr(time.getMonth() + 1) + "/" + getTwoLenNumStr(time.getDate()) + " " + getTwoLenNumStr(time.getHours()) + ":" + getTwoLenNumStr(time.getMinutes()); };
时间: 2024-04-01 16:32:47 浏览: 16
这段代码是用来格式化时间的,包含两个函数。其中getTwoLenNumStr函数是用来将数字转化为两位字符串的,如果数字小于10,则在前面添加一个0,否则直接返回该数字。而formatDate函数则是将时间戳转化为标准的年月日时分格式,返回一个字符串。具体实现是先将时间戳转化为Date对象,然后分别获取年月日时分秒,并使用getTwoLenNumStr函数将数字转化为两位字符串,最后将这些字符串拼接成标准格式返回。
相关问题
以下代码可以优化吗?如果可以请给出优化代码并注释const app = getApp(); function formatDate(date) { const year = date.getFullYear(); const month = date.getMonth() + 1; const day = date.getDate(); return `${year}-${month < 10 ? '0' + month : month}-${day < 10 ? '0' + day : day}`; } Page({ data: { visits: wx.getStorageSync('visits'), dateString: "", current: 0, laifangzongrenshu: "", filteredDataArray: [], }, you: function () { var that = this; var current = that.data.current; if (current < that.data.visits.length - 1) { that.setData({ current: current + 1, }) } let dateString = that.data.dateString; let date = new Date(dateString); date.setDate(date.getDate() + 1); let year = date.getFullYear(); let month = date.getMonth() + 1; let day = date.getDate(); let nextDay = year + '-' + (month < 10 ? '0' + month : month) + '-' + (day < 10 ? '0' + day : day); this.setData({ dateString: nextDay, }); }, zuo: function () { var that = this; var current = that.data.current; if (current > 0) { that.setData({ current: current - 1, }) } let dateString = that.data.dateString; let date = new Date(dateString); date.setDate(date.getDate() - 1); let year = date.getFullYear(); let month = date.getMonth() + 1; let day = date.getDate(); let prevDay = year + '-' + (month < 10 ? '0' + month : month) + '-' + (day < 10 ? '0' + day : day); this.setData({ dateString: prevDay, }); },})
可以对代码进行如下优化:
```js
const app = getApp();
function formatDate(date) {
const year = date.getFullYear();
const month = date.getMonth() + 1;
const day = date.getDate();
return `${year}-${month.toString().padStart(2, '0')}-${day.toString().padStart(2, '0')}`;
}
Page({
data: {
visits: wx.getStorageSync('visits'),
dateString: formatDate(new Date()),
current: 0,
},
you() {
const current = this.data.current;
if (current < this.data.visits.length - 1) {
this.setData({
current: current + 1,
});
}
const dateString = this.data.dateString;
const nextDate = new Date(new Date(dateString).getTime() + 24 * 60 * 60 * 1000);
this.setData({
dateString: formatDate(nextDate),
});
},
zuo() {
const current = this.data.current;
if (current > 0) {
this.setData({
current: current - 1,
});
}
const dateString = this.data.dateString;
const prevDate = new Date(new Date(dateString).getTime() - 24 * 60 * 60 * 1000);
this.setData({
dateString: formatDate(prevDate),
});
},
});
```
优化思路:
1. 将日期格式化代码封装成一个函数`formatDate`,并使用`padStart`函数补全日期格式中的0。
2. 在`data`中的`dateString`字段中,直接存储格式化后的当天日期,而不是默认为空字符串。
3. 在点击左右按钮时,使用`const`代替`var`,并直接在`setData`中更新数据。
4. 在点击左右按钮时,使用`new Date(dateString)`获取日期对象,而不是使用`new Date()`再转换成日期对象。
5. 在点击左右按钮时,使用`getTime()`获取日期的时间戳,再加上或减去24小时的毫秒数,最后使用`new Date()`将时间戳转换成日期对象。
这样做的好处是,代码更加简洁易读,同时也提高了代码的可维护性。
function formatDate(data) { for (var i = 0; i < data.length; i++) { var dateString = data[i].petition_at; var date = new Date(dateString); var year = date.getFullYear(); var month = ("0" + (date.getMonth() + 1)).slice(-2); var day = ("0" + date.getDate()).slice(-2); data[i].petition_at = year + "-" + month + "-" + day + " " + hours dateString = data[i].created_at; date = new Date(dateString); year = date.getFullYear(); month = ("0" + (date.getMonth() + 1)).slice(-2); day = ("0" + date.getDate()).slice(-2); data[i].petition_at = year + "-" + month + "-" + day + " " + hours data[i].created_at = date.toLocaleString(); } return data; } return data = formatDate(data)哪里有错
这段代码有几处小错误:
1. 在第一行的 `function formatDate(data)` 后面缺少一个左括号 `(`。
2. 在第三个 `var` 声明中,变量 `hours` 没有被定义,应该是 `date.getHours()`。
3. 在第六行和第九行,将 `petition_at` 改成了 `created_at`,这是无意义的,应该将第九行的 `petition_at` 改成 `created_at`。
下面是修正后的代码:
```
function formatDate(data) {
for (var i = 0; i < data.length; i++) {
var dateString = data[i].petition_at;
var date = new Date(dateString);
var year = date.getFullYear();
var month = ("0" + (date.getMonth() + 1)).slice(-2);
var day = ("0" + date.getDate()).slice(-2);
var hours = date.getHours();
data[i].petition_at = year + "-" + month + "-" + day + " " + hours;
dateString = data[i].created_at;
date = new Date(dateString);
year = date.getFullYear();
month = ("0" + (date.getMonth() + 1)).slice(-2);
day = ("0" + date.getDate()).slice(-2);
data[i].created_at = year + "-" + month + "-" + day + " " + hours;
data[i].petition_at = date.toLocaleString();
}
return data;
}
data = formatDate(data);
```