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.IntroductionIn Go, slices are a fundamental data structure used to work with sequences of elements. They are essentially a view into an underlying array, providing a flexible and powerful way to manipulate collections of ...

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 PointersIn Go, pointers are a fundamental type that stores the memory address of a variable. When a pointer is declared but not initialized, its value is nil. The following example code illustrates this:package mai...

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 rationale behind this starting with an example.func modifySlice(innerSlice []string) { innerSlice[0] ...

There are 3 components of slice:a) Pointer: Points to the start position of slice in the underlying array;b) length (type is int): the number of the valid elements of the slice;b) capacity (type is int): the total number of slots of the slice.Check the following code:package mainimport ( "fmt" "unsafe")func main() { var s1 []int fmt.Println(unsafe.Sizeof(s1))}The result is 24 on my 64-bit system (The pointer and int both occupy 8 bytes).In the next example, I will use gdb to poke the internals of slice. The code is like this:package mainimport "fmt"func main() { s1 := make([]int, 3, 5) ...