2021/6/9 javascript记忆

'''
parseInt()
parseFloat()
    .length
    .trim()
    .trimLeft()
    .trimRight()
    .charAt(index)
    .concat(obj)
    .indexOf(str, start)
    .substring(start, end)
    .slice(start, end)
    .split('', count)
    .toLowerCase()
    .toUpperCase()
    .match('re')

    typeof  xx

+ - * / % ++ --
> >= < <= != == !== ===
&& || !
+= -= /= *= %= =

if (){}else{}
if (){}else if (){}
switch (){case: xxx;break;default:xx;break}
for (;;){}
while () {}

function xxx(){}
var a = function(){}
(function(){})();
var a = b => b;

arguments

参数
局部变量
函数声明

    .length
    .push(obj)
    .unshift(obj)
    .pop()
    .shift()
    .reverse()
    .slice(start, end)
    .join(seq)
    .concat(obj)
    .sort(func)
    .forEach(func(value,index,obj), thisValue)
    .map(func(value,index,obj), thisValue)
    .splice(index, count,obj)

    var a = new Object()
    字符串 - 直
    var a = {k:v}

    var a = new Map()
    值对值
    a.set(key, value)
    a.get(key)
    a.has(key)
    a.delete(key)

    var a = new Date()
    'y/m/d h:m'
    'm/d/y h:m'
    getTime()
    y,m,d,h,m,s,ms
        .getYear()/Month/Date/Hours/Minutes/Seconds/Milliseconds
        .getFullYear()
        .toLocaleString()
        .getDay()
        .getTime()
    JSON.parse()
    JSON.stringify()
    var a = new RegExp('re')
    var a = /re/g;
        .test(string)
        .lastIndex = 0
    Math.
        abs/pow/round/floor/max/min/sin/tan/log()/exp()/random()
        sqrt()
    var a = FormData()
    obj = $(#id).files[0]
    a.readAsdataURL(obj)
    a.result
    a.append(k,v)


window
    .innerWidth
    .innerHeight
    .open('', '', '')
    .close()

    navigator
        .appName
        .appVerion
        .userAgent
        .platform

    screen
        .availWidth
        .availHeight

    history
        .back()
        .forward()

    location
        .href
        .href=''
        .reload()

    alert('')
    confirm('')
    prompt('', '')

    setTimeout('', ms)
    clearTimeout(id)
    setInterval('', ms)
    clearInterval(id)



DOM操作
   dom标准中归档html文档中每个成分都是一个节点
   文档节点：document：文档
   元素节点：element：代表标签
   属性节点：attribute：代表标签属性
   文本节点：text：代表标签文本
   注释节点：comment：注释

查找标签
    document.
        getElementById('')
        getElementsByClassName('')
        getElementsByTagName('')

            .parentElement
            .children
            .firstElementChild
            .lastElementChild
            .nextElementSibling
            .previousElementSibling

        var a = document.createElement('')
            .appendChild(a)
            .insertBefore(a, old)
            .innerText =''

            .removeChild(查找标签)

            .replaceChild(new, old)
        innerText = ''
        innerHTML

        setAttribute('', '')
        getAttribute('')
        removeAttribute('')

        .属性名
        .value
        .files  FileList

        .style.属性名

        classList
            .add('')
            .remove('')
            .contains('')
            .toggle('')




'''