Standard Library Cheatsheet

Last updated: Fri, 17 Jan 2020 18:42:31 GMT

Usage

吾嘗觀「「算經」」之書。方悟「正弦」「餘弦」「圓周率」之義。

Table of Contents

• 列經 - Array
• 易經 - Random
• 曆法 - Calendar
• 算經 - Math
• 籌經 - Collection Operations
• 位經 - Bit Manipulation
• 格物 - Object
• 畫譜 - Canvas

列經 - Array

Wenyan	Javascript Equivalent
遍施	Array.forEach
篩剔	Array.filter
排序	Array.sort
倒序	Array.reverse
擷取	Array.slice

易經 - Random

Wenyan	Javascript Equivalent

曆法 - Calendar

💬 This library uses your system timezone setting

Wenyan	Javascript Equivalent
今何紀元時	Date.now() / 1000
言今之日時	new Date().toString(), in Chinese calendar
言今之年月日	new Date().toDateString(), in Chinese calendar
言今之時刻	new Date().toTimeString(), in Chinese calendar
今年何年號	"西元" for modern dates
今年何年	new Date().getFullYear() for modern dates, in Chinese calendar
今年何干支	Get index (1 to 60) of this year in the 60-year cycle
今年積何年	new Date().getFullYear() + 2697, in Chinese calendar
今月何月	new Date().getMonth() + 1, N + 0.5 for leap months, in Chinese calendar
今月積何月	Get continuously counting month number of this month
今日何日	new Date().getDate(), in Chinese calendar
今日何干支	Get index (1 to 60) of today in the 60-day cycle
今日積何日	Get continuously counting day number of today
今時何時	Get index (1 to 12) of current time in the 12 divisions of day
今時何小時	new Date().getHours()
今刻何刻	Math.floor(new Date().getMinutes() / 15)
今分何分	new Date().getMinutes() % 15
今秒何秒	new Date().getSeconds()
言彼之日時	new Date(x * 1000).toString(), in Chinese calendar
言彼之年月日	new Date(x * 1000).toDateString(), in Chinese calendar
言彼之時刻	new Date(x * 1000).toTimeString(), in Chinese calendar
彼年何年號	"西元" for modern dates
彼年何年	new Date(x * 1000).getFullYear() for modern dates, in Chinese calendar
彼年何干支	Get index (1 to 60) in the 60-year cycle
彼年積何年	new Date(x * 1000).getFullYear() + 2697, in Chinese calendar
彼月何月	new Date(x * 1000).getMonth() + 1, N + 0.5 for leap months, in Chinese calendar
彼月積何月	Get continuously counting month number
彼日何日	new Date(x * 1000).getDate(), in Chinese calendar
彼日何干支	Get index (1 to 60) in the 60-day cycle
彼日積何日	Get continuously counting day number
彼時何時	Get index (1 to 12) in the 12 divisions of day
彼時何小時	new Date(x * 1000).getHours()
彼刻何刻	Math.floor(new Date(x * 1000).getMinutes() / 15)
彼分何分	new Date(x * 1000).getMinutes() % 15
彼秒何秒	new Date(x * 1000).getSeconds()

算經 - Math

Wenyan	Javascript Equivalent
圓周率	Math.PI
倍圓周率	Math.PI * 2
半圓周率	Math.PI / 2
四分圓周率	Math.PI / 4
自然常數	Math.E
歐拉常數	0.5772156649015329
黃金分割數	1.618033988749895
二之平方根	Math.SQRT2
二之對數	Math.LN2
十之對數	Math.LN10
不可算數乎	Number.isNaN
浮點移位	x * Math.pow(2, y), y is integer
析浮點數	N/A
取底除	{ 商: Math.floor(x / y), 餘: x - y * quo }
取整除	{ 商: Math.round(x / y), 餘: x - y * quo }
正弦	Math.sin
餘弦	Math.cos
反正弦	Math.asin
反餘弦	Math.acos
正切	Math.tan
反正切	Math.atan
勾股求角	Math.atan2
勾股求弦	Math.hypot
對數	Math.log
指數	Math.exp
冪	Math.pow
平方根	Math.sqrt
絕對	Math.abs
取頂	Math.ceil
取底	Math.floor
取整	Math.round, but rounded away from zero when the fractional part is exactly 0.5
捨餘	Math.trunc
正負	Math.sign

籌經 - Collection Operations

Wenyan	Javascript Equivalent
求和	reduce((a,b)=>a+b)

位經 - Bit Manipulation

Wenyan	Javascript Equivalent

格物 - Object

Wenyan	Javascript Equivalent

畫譜 - Canvas

Wenyan	Javascript Equivalent

Help update this cheatsheet

This cheatsheet is generated direct from stdlibs. There are still a lot of functions are not listed above. If you would like to hep update this cheatsheet, here is the steps.

Add comments in the stdlib files (one line above the function/value), the format should look like this:

注曰「「餘弦。同Javascript之Math.cos也。」」

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