How to find the length of the pointer in Golang?


In Golang, pointers are used to hold the memory addresses of other variables. They are often used to pass a variable's memory address to a function or to create a reference to an object in memory. The length of a pointer is determined by the size of the data type it points to. In this article, we will explore how to find the length of a pointer in Golang.

Understanding Pointers in Golang

Before we dive into finding the length of a pointer in Golang, let's first understand what pointers are and how they work in Golang.

In Golang, a pointer is a variable that stores the memory address of another variable. Pointers are denoted by an asterisk (*) followed by the variable name. For example, to declare a pointer to an integer variable, we can use the following syntax −

var ptr *int

Here, ptr is a pointer to an integer variable. To assign a value to a pointer, we use the address-of operator (&). For example −

var num int = 42
var ptr *int = &num

Here, we have created a variable num with a value of 42. We then created a pointer ptr to num using the address-of operator.

To access the value of a pointer, we use the dereference operator (*). For example −

fmt.Println(*ptr) // Output: 42

This will print the value of the integer variable num.

Finding the Length of a Pointer

In Golang, the length of a pointer is determined by the size of the data type it points to. To find the length of a pointer in Golang, we can use the unsafe package. The unsafe.Sizeof function returns the size in bytes of the given expression.

Example

Here is an example −

package main

import (
   "fmt"
   "unsafe"
)
func main() {
   var ptr *int
   fmt.Println(unsafe.Sizeof(ptr)) // Output: 8
}

Output

8

In this example, we have created a pointer ptr to an integer variable. We then used the unsafe.Sizeof function to find the size in bytes of ptr, which is 8 on a 64-bit system.

It's important to note that the unsafe package should be used with caution as it allows for potentially unsafe operations such as pointer arithmetic.

Conclusion

In this article, we have explored how to find the length of a pointer in Golang. We first learned what pointers are and how they work in Golang. We then used the unsafe package to find the size in bytes of a pointer. While pointers can be a powerful tool in Golang, they should be used with caution and only when necessary.

Updated on: 05-May-2023

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