We know that maps in Go contain key-value pairs. There are often instances where we would want to know that a certain key exists in a map or not, in such cases, we have two options available.The first approach is very naive, as in this approach, we basically iterate over the map with the help of the range clause and then compare each key to the key that we want to check if is available or not.And the second approach is a bit better, as we make use of the if statement with a bit of syntactic sugar.Let's first check ... Read More

We often want to replace certain strings or all the strings that match a pattern with some other string. In order to do that in Golang, we can either use the native functions that the strings package of Go's standard library provides us with or we can write the logic for the same on our own.In this article, we will see different examples, where we will use the two most used functions of the strings package. These functions are −strings.Replace()strings.ReplaceAll()Let's first consider the signature of these functions to know a little more about them.Syntax of strings.Replace()func Replace(s, old, new string, ... Read More

To read a CSV file in Go, the first thing that we need to make use of is the encoding/csv package that the Go standard library provides us with. The encoding/csv package contains different functions and methods that can be used when we want to read data from a CSV file.In this article, we will use the NewReader() function that the package provides, which takes one argument and that is basically the file that we want to open and then invoke the ReadAll() method on the file as well.Besides the encoding/csv package, we will also use the os package, which ... Read More

Many languages do provide a method similar to indexOf() where one can find the existence of a particular element in an array-like data structure. However, in Golang, there's no such method and we can simply implement it with the help of a for-range loop.Let's suppose we have a slice of strings, and we want to find out whether a particular string exists in the slice or not.Example 1Consider the code shown below.package main import (    "fmt" ) func Contains(sl []string, name string) bool {    for _, value := range sl {       if value == name ... Read More

Number parsing in Go is about converting the numbers that are present in string form to number form. By number form, we mean that these numbers can either be converted into integers, floats, etc.The most widely used package for number parsing is the "strconv" package that Go library provides us with. There are many cases that are present in the number parsing in Go, we will talk about all of these one by one in this article.The most basic approach is when we have a base 10 number that is actually present in a string form and we want to ... Read More

In Go, we have a package named time that is present in Go's standard library. This time package contains different useful functions that we can use to calculate the time taken by a code block or even a function in Go.The most widely used functions are time.Sleep(), time.Since() and time.Now(). In this article, we will see how to use all these functions.Let's first consider a very basic example where we will use all these functions.Example 1Consider the code shown below.package main import (    "fmt"    "time" ) func main() {    fmt.Println("Measuring time in Go")    start := time.Now() ... Read More

In order to understand what closures are, we must know what anonymous functions are and how we can use them.Anonymous functionsIn Go, anonymous functions are those functions that don't have any name. Simply put, anonymous functions don't use any variables as a name when they are declared.We know that we declare a function with a similar syntax as shown below.func Sample(){    // some code }While we do have a name for the above function (Sample), in the case of anonymous functions, we don't have one.What is the closure function?Closure functions are the anonymous functions that have access to their ... Read More

We know that every code in Golang is present inside a package, which can either be an executable one or a utility one. The executable package name is usually main and the name of the utility package can be anything, in most cases, it is the name of the folder.Suppose we have a directory structure that looks something like this.. |-- greet |    `-- greet.go |-- sample |    `-- sample.goWe have two directories, namely, greet and sample, and each of them contains a single .go file inside them. Now, we want to make use of a function that ... Read More

To read a file into a string, we need to make use of the io/ioutil package that Go's standard library provides us with.Inside the io/ioutil package, there's a function called ReadFile() which is used to open a file and then convert its contents into a slice of bytes, and if for some reason, it isn't able to do so, then it will return an error too.Here is the syntax of the ReadLine() function.func ReadFile(filename string) ([]byte, error)It should be noted that if the above function has made a successful call, then it will return err == nil, not err == ... Read More

Suppose we want to read a JSON file in Go. By reading, we mean that we want to convert the file data into a struct in Go.Consider the JSON file shown below that we will use to read and then convert the data into the structure.{    "users": [       {          "name": "Mukul Latiyan",          "social": {             "facebook": "https://facebook.com/immukul",             "twitter": "https://twitter.com/immukul",             "linkedin": "https://linkedin.com/immukul"          }       },   ... Read More