使用HTMLInputElement.prototype.valueAsDate:

document.getElementById('datePicker').valueAsDate = new Date();

HTML

<input type="date" id="theDate">

JQuery

$(document).ready(function() {
    var date = new Date();

    var day = date.getDate();
    var month = date.getMonth() + 1;
    var year = date.getFullYear();

    if (month < 10) month = "0" + month;
    if (day < 10) day = "0" + day;

    var today = year + "-" + month + "-" + day +"T00:00";       
    $("#theDate").attr("value", today);
});

demo

如果你不想使用jQuery，你可以这样做

JS

var date = new Date();

var day = date.getDate();
var month = date.getMonth() + 1;
var year = date.getFullYear();

if (month < 10) month = "0" + month;
if (day < 10) day = "0" + day;

var today = year + "-" + month + "-" + day;       
document.getElementById("theDate").value = today;

demo

TS

const date = new Date()
const year = date.getFullYear()

let month: number | string = date.getMonth() + 1
let day: number | string = date.getDate()

if (month < 10) month = '0' + month
if (day < 10) day = '0' + day

const today = `${year}-${month}-${day}`    
document.getElementById("theDate").value = today;

这依赖于PHP:

<input type="date" value="<?php echo date('Y-m-d'); ?>" />

使用HTMLInputElement.prototype.valueAsDate:

document.getElementById('datePicker').valueAsDate = new Date();

new Date().getFullYear()+"-"+ ((parseInt(new Date().getMonth())+1+100)+"").substring(1)

这是非常简单的应用下面的代码，使用PHP

<input type="date" value="<?= date('Y-m-d', time()); ?>" />

Date函数将通过Date in time()返回当前日期。