thinkerou / 30-seconds-of-go

Curated collection of useful Go snippets you can understand in 30 seconds or less.

30 seconds of Go

Curated collection of useful Go snippets that you can understand in 30 seconds or less.

Note: The project is inspired by 30 seconds of code, but there is no affiliation with that project.

Installation

⚠️ NOTICE: A few of our snippets are not yet optimized for production (see disclaimers for individual snippet issues).

To install this package, you need to install Go and setup your Go workspace on your computer. The simplest way to install the library is to run:

$ go get -u github.com/thinkerou/30-seconds-of-go

Prerequisites

This requires Go 1.12 or later.

Table of Contents

🔌 Adapter

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📚 Array

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⏱️ Date

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🎛️ Function

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➗ Math

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• average
• averageBy
• fibonacci
• gcd
• isEven
• isPowerOf2
• isPrime

🗃️ Object

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📜 String

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📃 Type

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🔧 Utility

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---

➗ Math

average

Returns the average of two or more numbers.

Examples

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averageBy

Returns the average of an array, after mapping each element to a value using the provided function.

Examples

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fibonacci

Geerates an array, containing the Fibonacci sequence, up until the nth term.

Examples

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gcd

Calculates the greatest common divisor between two or more numbers/arrays.

Examples

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isEven

Returns true if the given number is even, false otherwise.

Checks whether a number is odd or even using the modulo (%) operator or and (&) operator. Returns true if the number is even, false if the number is odd.

func isEven(i int) bool {
	return i % 2 == 0
}

func isEven(i int) bool {
	return i & 1 == 0
}

Examples

isEven(-1) // false
isEven(-2) // true
isEven(3) // false
isEven(4) // true

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isPowerOf2

Returns true is the given positive integer is the power of 2, false otherwise.

Checks whether a positive integer is the power of 2 using the and (&) operator.

func is PowerOf2(i uint) bool {
	return i & (i -1) == 0
}

Examples

isPowerOf2(1) // true
isPowerOf2(2) // true
isPowerOf2(3) // false
isPowerOf2(4) // true

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isPrime

Checks if the provided integer is a prime number.

Check numbers from 2 to the square root of the given number. Return false if any of them divides the given number, else return true, unless the number is less than 2.

func isPrime(n int) bool {
	boundary := int (math.Floor(math.Sqrt(float64 (n))))
	for i := 2;  i <= boundary; i++ {
		if n % i == 0 {
			return false
		}
	}
	return n >= 2
}

Examples

isPrime(0) // false
isPrime(1) // false
isPrime(2) // true
isPrime(3) // true
isPrime(4) // false
isPrime(11) // true

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