import * as foo from "...";
import { Foo, Bar } from "...";
import defaultExport from "...";
import "...";
export const SOME_CONSTANT = ...
export function someHelpfulFunction()
export class Foo { }
export default ... // Deprecatedlet foo = false;
let bar = true;
bool.toString();
bool.valueOf();
let foo = 0b1111 + 0777 + 999 + 0xff;
let bar = 2.5 + 2 + 0.5 + 2e9 + 2.5e9;
let pinf = +Infinity;
let ninf = -Infinity;
let nan = NaN;
Number.MAX_VALUE;
Number.MIN_VALUE;
Number.NaN;
Number.NEGATIVE_INFINITY;
Number.POSITIVE_INFINITY;
Number.EPSILON;
Number.MIN_SAFE_INTEGER;
Number.MAX_SAFE_INTEGER;
Number.parseFloat(string);
Number.parseInt(string);
Number.isFinite(value);
Number.isInteger(value);
Number.isNaN(value);
Number.isSafeInteger(value);
number.toExponential(fractionDigits);
number.toFixed(digits);
number.toPrecision(precision);
let string = new String(thing)
let str1 = 'single quote'
let str2 = "double quote"
let str3 = `${expr}, and remain black charactor`
String.fromCharCode(...charCodes)
string.length
string.charAt(idx) // 返回string[idx]
string.charCodeAt(idx) // 返回unicode数字
string.indexOf(searchvalue, start=0)
string.lastIndexOf(searchvalue, start=searchvalue.length-1) // start表示最后一个字符用于匹配searchvalue的beginning
string.startsWith(searchvalue, start=0)
string.endsWith(searchvalue, length=searchvalue.length)
let regex = /pattern/flag
string.search(regexp) // 返回下标
string.match(regexp) // 返回数组
string.replace(regexp, newvalue)
string.split(separator="regexp", limit=Infinity)
string.concat(...strings)
string.repeat(count)
string.substr(start, length)
string.substring(start, end)
string.slice(start, end) // 支持类似python slice
string.toLowerCase()
string.toUpperCase()
string.trim()
JSON.parse(string)
JSON.stringify(object)
| flag |
说明 |
| g |
多次匹配 |
| i |
忽略大小写 |
| m |
多行搜索 |
| s |
允许.匹配换行符 |
| u |
unicode 模式 |
| y |
执行“粘性(sticky)”搜索,匹配从目标字符串的当前位置开始 |
let date = new Date(); // 当前时间
let date1 = new Date(number); // Unix时间戳，单位ms
let date2 = new Date(dateString);
let date3 = new Date(year, monthIndex [, day [, hours [, minutes [, seconds [, milliseconds]]]]]);
Date.now() // 返回当前Unix时间戳，单位ms
Date.parse(string)
Date.UTC(year,month[,date[,hrs[,min[,sec[,ms]]]]]) // 返回返回对应Unix时间戳，单位ms
date.getFullYear() //Returns the year
date.getMonth() //Returns the month (from 0-11)
date.getDate() //Returns the day of the month (from 1-31)
date.getDay() //Returns the day of the week (from 0-6)
date.getHours() //Returns the hour (from 0-23)
date.getMinutes() //Returns the minutes (from 0-59)
date.getSeconds() //Returns the seconds (from 0-59)
date.getMilliseconds() //Returns the milliseconds (from 0-999)
date.getTime() //Returns the number of milliseconds since midnight Jan 1 1970, and a specified date
date.getTimezoneOffset()//Returns the time difference between UTC time and local time, in minutes
date.getUTCFullYear() //Returns the year, according to universal time
date.getUTCMonth() //Returns the month, according to universal time (from 0-11)
date.getUTCDate() //Returns the day of the month, according to universal time (from 1-31)
date.getUTCDay() //Returns the day of the week, according to universal time (from 0-6)
date.getUTCHours() //Returns the hour, according to universal time (from 0-23)
date.getUTCMinutes() //Returns the minutes, according to universal time (from 0-59)
date.getUTCSeconds() //Returns the seconds, according to universal time (from 0-59)
date.getUTCMilliseconds()//Returns the milliseconds, according to universal time (from 0-999)
date.setFullYear() //Sets the year of a date object
date.setMonth() //Sets the month of a date object
date.setDate() //Sets the day of the month of a date object
date.setHours() //Sets the hour of a date object
date.setMinutes() //Set the minutes of a date object
date.setSeconds() //Sets the seconds of a date object
date.setMilliseconds() //Sets the milliseconds of a date object
date.setTime() //Sets a date to a specified number of milliseconds after/before January 1, 1970
date.setUTCFullYear() //Sets the year of a date object, according to universal time
date.setUTCMonth() //Sets the month of a date object, according to universal time
date.setUTCDate() //Sets the day of the month of a date object, according to universal time
date.setUTCHours() //Sets the hour of a date object, according to universal time
date.setUTCMinutes() //Set the minutes of a date object, according to universal time
date.setUTCSeconds() //Set the seconds of a date object, according to universal time
date.setUTCMilliseconds()//Sets the milliseconds of a date object, according to universal time
date.toString() //Converts a Date object to a string
date.toDateString() //Converts the date portion of a Date object into a readable string
date.toTimeString() //Converts the time portion of a Date object to a string
date.toUTCString() //Converts a Date object to a string, according to universal time
date.toISOString() //Returns the date as a string, using the ISO standard
date.toJSON() //Returns the date as a string, formatted as a JSON date
date.toLocaleDateString()//Returns the date portion of a Date object as a string, using locale conventions
date.toLocaleTimeString()//Returns the time portion of a Date object as a string, using locale conventions
date.toLocaleString() //Converts a Date object to a string, using locale conventions
let array = new Array(length=1)
let arr1 = [...elements]
let extend = [...array] // 展开，还可用于函数调用
let [v1, v2, ...rest] = array // 解构，不必完全解构数组内容
array[idx] // 若idx超出范围则返回undefined
array[idx] = value // 若idx超出范围则填充undefined；若idx非整数则作为属性
array.length
Array.from(object) // object with a length property or any iterable object
Array.isArray(obj)
array.indexOf(searchElement, start=0])
array.lastIndexOf(searchElement, start=searchElement.length-1)
array.find(function(curValue, curIndex=, array=), thisValue=);
array.findIndex(function(curValue, curIndex=, array=), thisValue=);
array.forEach(function(curValue, curIndex=, array=), thisValue=);
array.filter(function(curValue, curIndex=, array=), thisValue=);
array.map(function(curValue, curIndex=, array=), thisValue=);
array.reduce(function(total, curValue=, curIndex=, array=), initialValue);
array.reduceRight(function(total, curValue=, curIndex=, array=), initialValue);
array.every(function(curValue, curIndex=, array=), thisValue=);
array.some(function(curValue, curIndex=, array=), thisValue=);
array.join(deliminator = ',')
array.concat(...arrays)
array.copyWithin(target, start, end)
array.push(...items)
array.pop()
array.unshift(...items)
array.shift()
array.splice(index, count_to_remove, addElement1, addElement2, ...)
array.slice(start_index, upto_index)
array.reverse()
array.sort(compareFunction)
array.fill(value, start, end)
array.keys()
array.entries()
let set = new Set()
let wset = new WeakSet() // 对象弱引用集合，key必须为object
let extend = [...set]; // 展开，还可用于函数调用
let [v1, v2, ...rest] = set;// 解构，不必完全解构数组内容
set.size
set.has(value)
set.add(value)
set.delete(value)
set.clear()
set.keys()
set.values()
set.entries()
set.forEach(function(curValue, curIndex=, set=), thisValue=);
let map = new Map()
let map = new Map([[key, val], [key, val]])
let wmap = new WeakMap() // 对象弱引用集合，key必须为object
Array.from(map) // [[key, val], [key, val]]
let extend = [...map]; // 展开，还可用于函数调用
let [pair, [key, val]] = map; // 解构，不必完全解构数组内容
map.size
map.has(key)
map.set(key, val)
map.get(key) // 若不存在则返回undefined
map.delete(key)
map.keys()
map.values()
map.entries()
map.forEach(function(curValue, curKey=, map=), thisValue=);
let obj = {
name: 'xhc',
age: 21,
} // obj本质就是key类型为string的hashmap
obj.name // 若key的字符串内容符合标识符规范则可用该语法
obj['age'] // 否则只能使用方括号下标法
let extend = {...obj} // 展开，一种copy手法
let {k1, k2, ..rest} = obj // 解构，不必完全解构内容
function({k1, k2}) // 解构，可用于函数调用
let {keyName: val} = obj // 解构，非规范属性名
let {['keyName']: val} = obj// 同上，先计算keyName
Object.keys(o)
Object.getOwnPropertyNames(o)eval();
encodeURI();
decodeURI();
encodeURIComponent();
decodeURIComponent();