# common-constants I find myself defining the same constants in project after project. Time to put a stop to that. ## Installation yarn add common-constants OR npm add --save common-constants Exports an object literal containing a set of common constants. Categories: * date and time (constants.datetime) * math (constants.math) * default ports for various databases and servers (constants.defaultPorts), * science (constants.science) * common log levels and corresponding numeric values (constants.logLevels) I am forgetful, so it was made to be extremely forgiving, with multiple variants of each constant name allowed. e.g. minInHour, minPerHour, minInHr, minPerHr, minutesPerHour, minutesPerHr, etc.). Also, it's typescript friendly, because I love you guys. ## Why? Magic numbers are confusing. If you see an algorithm containing the number 60, what are you looking at exactly? Seconds per minute? Minutes per hour? Degrees in one sixth of a circle? Named constants get rid of the problem ---- ## Usage example import { datetime } as DATETIME_CONST from 'common-constants'; console.log(DATETIME_CONST.daysPerMonth.jan); // => 31 console.log(DATETIME_CONST.daysPerCommonYear); // => 365 console.log(DATETIME_CONST.hrPerDay); // => 24 ---- ## Date and time values (constants.datetime) // Leap year handler (technically not a constant, but it's commonly needed when date constants are required) isLeap: (year: number | string) => boolean Returns true if the given year is a leap year, false if not // Microseconds per millisecond microsecondsPerMillisecond: 1000 microsecondsPerMs: 1000 usPerMs: 1000 usecondsPerMs: 1000 usPerMillisecond: 1000 usecondPerMillisecond: 1000 usecondsPerMillisecond: 1000 μPerMs: 1000 μsPerMs: 1000 μsecondsPerMs: 1000 μPerMillisecond: 1000 μsecondPerMillisecond: 1000 μsPerMillisecond: 1000 μsecondsPerMillisecond: 1000 // Milliseconds per second msPerSec: 1000 millisecondsPerSecond: 1000 msPerSecond: 1000 msPerSeconds: 1000 millisecondsPerSec: 1000 // Milliseconds per minute msPerMinute: 60000 millisecondsPerMinute: 60000 msPerMin: 60000 millisecondsPerMin: 60000 // Milliseconds per hour msPerHour: 3600000 millisecondsPerHour: 3600000 msPerHr: 3600000 millisecondsPerHr: 3600000 // Milliseconds per day msPerDay: 86400000 millisecondsPerDay: 86400000 // Milliseconds per year (common and leap) msPerCommonYear: 31536000000 millisecondsPerCommonYear: 31536000000 msPerLeapYear: 31622400000 millisecondsPerLeapYear: 31622400000 // Seconds per minute secPerMin: 60 secsPerMin: 60 secondsPerMinute: 60 secPerMinute: 60 secsPerMinute: 60 // Seconds per hour secPerHr: 3600 secsPerHr: 3600 secPerHour: 3600 secsPerHour: 3600 secondsPerHour: 3600 secondsPerHr: 3600 //Seconds per day secPerDay: 86400 secsPerDay: 86400 secondPerDay: 86400 secondsPerDay: 86400 //Seconds per week secPerWeek: 604800 secsPerWeek: 604800 secondPerWeek: 604800 secondsPerWeek: 604800 // Seconds per year (common and leap) secPerCommonYear: 31536000 secondsPerCommonYear: 31536000 secPerLeapYear: 31622400 secondsPerLeapYear: 31622400 // Minutes per hour minPerHr: 60 minPerHour: 60 minutesPerHour: 60 minutesPerHr: 60 // Minutes per day minPerDay: 1440 minutesPerDay: 1440 // Minutes per week minPerWeek: 10080 minutesPerWeek: 10080 // Minutes per year (common and leap) minPerCommonYear: 525600 minutesPerCommonYear: 525600 minPerLeapYear: 527040 minutesPerLeapYear: 527040 // Hours per day hrPerDay: 24 hrsPerDay: 24 hoursPerDay: 24 // Hours per week hrPerWeek: 168 hrsPerWeek: 168 hoursPerWeek: 168 // Hours per year (common and leap) hrPerCommonYear: 8760 hrsPerCommonYear: 8760 hoursPerCommonYear: 8760 hrPerLeapYear: 8784 hrsPerLeapYear: 8784 hoursPerLeapYear: 8784 // Days per week daysPerWeek: 7 // Days per year (common and leap) daysPerCommonYear: 365 daysPerCommonYr: 365 daysPerLeapYear: 366 daysPerLeapYr: 366 daysPerYrAverage: 365.25 daysPerYrMean: 365.25 daysPerYearAverage: 365.25 daysPerYearMean: 365.25 // Weeks per year (common and leap) weeksPerYear: full: 52 rem: common: 1 leap: 2 weeksPerCommonYear: 365 / 7 weeksPerLeapYear: 366 / 7 fullWeeksPerYear: 52 weeksPerYearFloored: 52 weeksPerCommonYearFlooredRemainder: 1 weeksPerLeapYearFlooredRemainder: 2 // Months per year monthsPerYear: 12 monPerYear: 12 monsPerYear: 12 monPerYr: 12 monsPerYr: 12 monthsPerYr: 12 // Days per month daysPerMon: daysPerMonth // see 'daysPerMonths' property below daysPerMonth: jan: 31 january: 31 feb: common: 28 leap: 29 february: common: 28 leap: 29 mar: 31 march: 31 apr: 30 april: 30 may: 31 jun: 30 june: 30 jul: 31 july: 31 aug: 31 august: 31 sep: 30 sept: 30 september: 30 oct: 31 october: 31 nov: 30 november: 30 dec: 31 december: 31 // Unix / epoch start date & time components epochStartYear: 1970 epochStartMonth: 1 epochStartDate: 1 epochStartHour: 0 epochStartMinute: 0 epochStartSecond: 0 epochStartDateStr: '1970-01-01' epochStartTimeStr: '00:00:00.000Z' epochStartDateTimeStr: '1970-01-01T00:00:00.000Z' unixStartYear: 1970 unixStartMonth: 1 unixStartDate: 1 unixStartHour: 0 unixStartMinute: 0 unixStartSecond: 0 unixStartDateStr: '1970-01-01' unixStartTimeStr: '00:00:00.000Z' unixStartDateTimeStr: '1970-01-01T00:00:00.000Z' ---- ## Math pi: 3.141592653589 PI: 3.141592653589 π: 3.141592653589 e: 2.718281828459 euler: 2.718281828459 EULER: 2.718281828459 phi: 1.6180339887498 PHI: 1.6180339887498 φ: 1.6180339887498 // Geometry: circle degreesInCircle: 360 degInCircle: 360 circleDeg: 360 circleDegrees: 360 // Geometry: half-circle degreesInHalfCircle: 180 degInHalfCircle: 180 halfCircleDeg: 180 halfCircleDegrees: 180 // Geometry: right angle rightAngleDeg: 90 rightAngleDegrees: 90 rightAngle: 90 // Geometry: sides in a square sidesInSquare: 4 sidesInASquare: 4 squareSides: 4 numSidesSquare: 4 // Geometry: sides in a triangle sidesInTriangle: 3 sidesInATriangle: 3 triangleSides: 3 numSidesTriangle: 3 ---- ## Default ports (constants.defaultPorts) dbPorts: [1025, 1433, 1521, 1522, ..., 6379, 7199, 8983, 9200, 27017, 27018, 50000], all: redis: 6379 mongo: 27018 mongodb: 27018 postgres: 5432 postgresql: 5432 pg: 5432 mysql: 3306 express: 3000 expressjs: 3000 expressJS: 3000 expressJs: 3000 http: 80 telnet: 23 smtp: 25 dns: 53 pop3: 110 irc: 194 https: 443 ssh: 22 ...etc... ---- ## Log levels - as numeric values (constants.logLevels) silly: 1 verbose: 2 debug: 3 info: 4 warn: 5 error: 6 wtf: 7 ---- ## Life, the universe, and everything lifeTheUniverseAndEverything: 42 ---- ## Science speedOfLightMetresPerSec: 299792458 speedOfLightMetresPerSecond: 299792458 speedOfLightMPS: 299792458 lightSpeedMetresPerSec: 299792458 lightSpeedMetresPerSecond: 299792458 zeroKelvinInCelsius: -273.15 zeroKInCelsius: -273.15 zeroKelvinInC: -273.15 ---- More coming soon.