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SEARCH KEYWORD -- Pointer



  C/C++ Pointer Declaration Syntax – It makes sense!

I never really liked the way pointers are declared in C/C++: int *a, *b, *c; // a, b and c are pointers to int The reason is that I am used to reading variable declarations as MyType myVar1, myVar2, myVar3; and I always read “int*” as the type “integer pointer”. I therefore wanted the following int* a, b, c; // a is a pointer to int, b and c are ints to mean that a, b and c all were of type int*, i.e. pointers to int. and I therefore found it slightly a...

   C,Pointer,Declaration,Attempt     2012-02-22 05:43:58

  Understand unsafe in GoLang

Before going to understand unsafe package in GoLang, the first thing needs to talk about is the pointer in GoLang. If you have a background of C language, you must know what pointer means and its usage. With pointer, you are free to operate any data at memory level which means you have great power, but this means that you have great responsibility as well. That's why it might be considered unsafe in lots of cases. Take a look at a simple example of doubling an integer. package main import "fmt"...

   GOLANG,UNSAFE,ZERO-COPY     2020-03-14 23:18:00

  Smuggling data in pointers

While reading up on The ABA Problem I came across a fantastic hack.  The ABA problem, in a nutshell, results from the inability to atomically access both a pointer and a "marked" bit at the same time (read the wikipedia page).  One fun, but very hackish solution is to "smuggle" data in a pointer.  Example:#include "stdio.h"void * smuggle(void * ptr, int value){  return (void *)( (long long)ptr | (value & 3) );}int recoverData(void * ptr){  return (long long)ptr &...

   C,Pointer,Bit,Data,Atomic,Smuggle     2011-11-14 08:15:59

  Be careful about nil check on interface in GoLang

nil check is frequently seen in GoLang code especially for error check since GoLang's special error handling convention. In most cases, nil check is straight forward, but in interface case, it's a bit different and special care needs to be taken. Take a look at below code snippet and guess what the output will be. package main import ( "bytes" "fmt" "io" ) func check(w io.Writer) { if w != nil { fmt.Println("w is not nil") } fmt.Printf("w is %+v\n", w) } func main() { var b *bytes.B...

   INTERFACE,GOLANG,NIL CHECK,NIL TYPE,NIL VALUE     2019-04-06 07:47:07

  Understanding Slice Behavior in Go

In Go, understanding how slices behave when passed to functions is crucial for writing efficient and bug-free code. This behavior is often a source of confusion for many developers, especially those new to the language. In this article, we'll explore the difference between passing slices by value and by reference, and how it impacts the modification of slices within functions. Introduction In Go, slices are a fundamental data structure used to work with sequences of elements. They are essentiall...

   PASS BY REFERENCE,ARRAY,SLICE,PASS BY VALUE     2024-03-10 06:43:51

  The hidden risk of passing slice as function parameter

In Go's source code or other open source libraries, there are lots of cases where a slice pointer is passed to function instead of slice itself. This brings up a doubt why not passing slice directly as its internal is backed by an array pointer to point to underlying data? For example, in log package, the formatHeader function takes a parameter buf as type *[]byte instead of []byte. func (l *Logger) formatHeader(buf *[]byte, t time.Time, file string, line int) {} Let's understand the r...

   GOLANG,SLICE,SLICE POINTER     2020-12-13 06:11:14

  Algorithm : Delete middle node from singly linked list

Questions about singly linked list are frequently asked during technical interviews. Today we will share with you one algorithm question about singly linked list. Here is the problem description. Assuming the only information you are giving is there is a pointer to a middle node of a singly linked list, no other information about the linked list is given. Please delete this node and don't affect the structure of the linked list. Initially you may think this question is easy if you know the hea...

   ALGORITHM,C,LINKED LIST     2015-10-30 05:21:25

  How to Understand and Use nil in Golang Correctly?

In Golang, nil is a predefined identifier that carries different meanings in various contexts, but typically represents "none", "empty" or "zero value". It can be assigned to variables of pointer, slice, map, channel, function, and interface types. Understanding the significance of nil is crucial for writing robust Go programs, as mishandling nil can lead to unexpected issues. nil in Pointers In Go, pointers are a fundamental type that stores the memory address of a variable. When a pointer is d...

   FUNCTION,SLICE,MAP,CHANNEL,GOLANG,NIL     2024-01-05 05:19:40

  Why using anchors as buttons sucks

So let's say you're an awesome web developer making an awesome web app. One day, you add a link in the web app that has an event handler instead of an href. Testing it, you realize that your cursor doesn't change when hovering over it, unlike a normal link. You think for a minute and then give it a cursor:pointer style, which fixes the issue. You are happy.The next day, QA informs you that the link cannot be tabbed to. Confused, you do some research and find a solution to the problem: Sim...

   Anchor,Button,Link,Sucks     2012-02-05 07:22:39

  The Go Pointer Magic

Go is a language with the pointer type, by which we can Pass pointer into a function and update value in-place. Add methods to a struct as (* T) A, which is different from (T) A(). However, the pointer is type-safe in Go, meaning that there are such restrictions of the pointer. Different types of pointers are unconvertible. Pointer type cannot be used for calculation. Pointer types cannot be compared, either == nor !=. No mutual assignment between different pointer-...

   GOLANG,POINTER,UNSAFE     2021-10-03 02:18:57