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Showing posts from December, 2022

Concurrency examples

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 Concurrency examples 1. Go program that uses the sync package's WaitGroup type to wait for a group of goroutines to finish. The main function creates a WaitGroup value and calls its Add method with a value of 5 to specify that it is waiting for 5 goroutines to finish. Then it starts 5 goroutines by calling the Square function in a loop, passing the loop index and a pointer to the WaitGroup value as arguments. The Square function takes an integer no and a pointer to a WaitGroup value as arguments. It calculates the square of no and prints it along with the value of no. After that, it calls the Done method on the WaitGroup value to indicate that it has finished. The defer statement ensures that the Done method is called even if the function panics or returns early. Finally, the main function calls the Wait method on the WaitGroup value to block until all the goroutines have finished. This ensures that the program doesn't exit before all the goroutines have completed their work.

Pointers

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 Pointers  In computer programming, a pointer is a variable that stores the memory address of another variable. Pointers are used to store the addresses of other variables, which can be used to access and manipulate the value stored in the other variables. They are a powerful tool that can be used to improve the efficiency of a program, but they can also be difficult to use correctly and can lead to bugs if not handled carefully. Pointers can be used to pass variables by reference to functions, allowing the function to modify the value of the variable. They can also be used to dynamically allocate memory at runtime, which can be useful for creating data structures like linked lists and trees. Pointers are used in computer programming for several reasons: Efficiency : Pointers allow you to directly manipulate the memory location of a variable, rather than copying the value of the variable to a new location. This can be more efficient in terms of time and memory usage. Dynamic memory all

Functions and Methods

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 Function in general  In programming, a function is a block of code that performs a specific task. Functions allow you to organize your code into logical units and reuse them throughout your program. Functions in Golang  In Go, a function is a block of code that performs a specific task and can optionally return a value. Go functions are defined using the func keyword, followed by the function name, a list of parameters, and the function body. Here is an example of a simple function in Go that takes two integers as arguments and returns their sum: Go functions can have multiple return values. For example: In this example, the divmod function takes two integers as arguments and returns their quotient and remainder when one is divided by the other. The function is called with the values 7 and 3, and the returned values are assigned to the variables quotient and remainder. Anonymous function Go also supports anonymous functions, which are functions without a named identifier. Anonymous fu

Slices

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Array Array : collection of the same type with continuous memory. Go’s arrays are values (value type) means whenever you assign an array to a new variable then the copy of the original array is assigned to the new variable. This is also called as deep copy The main issue an array has is that it can not be resized. Arrays do not need to be initialized explicitly; the zero value of an array is a ready-to-use array whose elements are themselves zeroed To overcome this problem we have  Slices in golang. Array example: Slices  Slices are the wrapper over arrays. Slices do not own any data of their own, they are just a reference to the existing array. Slices have length and capacity.  Length is the number of elements present in the slice, Capacity is the number of elements present in the underlying array. New elements can be added to the slice using  append function. // Slices var s [] byte // func make([]T, len, cap) []T // where T stands for the element type of the slice to be c

Interview Questions and Answers 1

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 Interview Questions and Answers 1 1. Does golang have any interpreter? Go is a compiled programming language, which means that it does not have an interpreter. Instead, Go programs are compiled into native machine code that can be directly executed by the computer's hardware. The process of compiling a Go program involves translating the source code of the program into machine code that can be executed by the computer's processor. This is done using a compiler, which is a specialized program that translates the source code of a program into machine code. The Go compiler is called gc , and it is included as part of the Go toolchain. To compile a Go program, you can use the go build command, which will invoke the Go compiler to compile the program and generate an executable binary file. In contrast, interpreted languages such as Python or JavaScript are executed by an interpreter, which reads and executes the source code of the program at runtime. Interpreted languages do not ne

Channels

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 Channels in golang Channel Channels are used in Go to allow communication between goroutines and to synchronize their execution. Goroutines are lightweight threads of execution that are multiplexed onto a single OS thread, and channels provide a way for goroutines to communicate with each other and coordinate their actions. One of the main benefits of using channels is that they allow you to write concurrent programs that are easy to reason about. By using channels to pass data between goroutines, you can structure your concurrent programs in a way that is easy to understand and debug. In addition, channels provide a way to synchronize the execution of goroutines.  For example, you can use a channel to wait for a goroutine to complete before moving on to the next step in your program. In Go, concurrency is achieved through the use of goroutines and channels. There are several advantages to using channels in Go: Channels provide a way to communicate between goroutines and synchronize t

Interfaces

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 Interfaces in Golang What is Interface  In general, an interface is a set of methods or behaviors that a type must implement in order to be considered an implementation of that interface. Interfaces are a way of specifying a contract that a type must adhere to in order to be used in a certain context. Interfaces are a common feature in many programming languages, and they are often used to define the behavior of types in a way that is decoupled from their implementation. This allows you to write code that is more flexible and easier to extend, as you can use different implementations of an interface without having to change the code that uses the interface. For example, you might define an interface called Shape that defines methods for calculating the area and perimeter of a shape. You could then define multiple types that implement the Shape interface, such as Rectangle, Circle, and Triangle. This would allow you to write code that works with any type that implements the Shape inter

Concurrency in Golang

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 Concurrency in Golang What is concurrency Concurrency is the ability of a system or program to have multiple tasks in progress at the same time.  It is a way of designing and organizing a system to allow multiple tasks to overlap in their execution, rather than executing them sequentially one after the other. Concurrency is often used in the context of computer programming,  where it allows multiple tasks to be performed concurrently within a single program.  It can be used to improve the performance and responsiveness of a program by allowing it to perform multiple tasks at the same time, rather than executing them one at a time in a sequential manner. There are several different ways to implement concurrency in a program, including: Multi threading : This involves dividing a program into multiple threads of execution that can run concurrently on separate cores or processors. Asynchronous programming : This involves using asynchronous functions or methods that allow a program to perf

Why Golang

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Why Golang History  Go, also known as Golang, is a programming language developed at Google in 2009 by Robert Griesemer, Rob Pike, and Ken Thompson.  It was designed to be a high-performance language that would be easy to use and maintain, with support for concurrency and garbage collection. Go was influenced by several other programming languages, including C, C++, and Pascal.  It has a syntax that is similar to C, but with some additional features that make it more modern and easier to use. One of the main goals of Go was to improve upon some of the shortcomings of existing programming languages, such as the slow compilation times and complex build processes of languages like C++.  Go was designed to be easy to build and deploy, with a simple, straightforward syntax that is easy to read and write. How Different from other languages Go is a general-purpose programming language that is designed to be simple, efficient, and easy to use.  It is different from other languages in a number