How to find the capacity of the pointer in Golang?


In Golang, pointers are variables that store the memory address of another variable. They are often used to reference large data structures and avoid copying the entire data structure. In addition to the memory address, a pointer also has a capacity. The capacity of a pointer is the maximum number of elements that can be stored in the memory block it references.

Finding the capacity of a pointer is an important task for any Golang developer. In this article, we will explore how to find the capacity of a pointer in Golang.

Understanding Pointers in Golang

Before diving into the capacity of a pointer, it is important to have a basic understanding of pointers in Golang. In Golang, a pointer is declared using the * symbol before a variable name. For example, var p *int declares a pointer to an integer variable.

A pointer can be assigned the memory address of a variable using the & symbol. For example, p = &x assigns the memory address of variable x to pointer p.

To access the value of the variable at the memory address pointed to by a pointer, we use the * symbol before the pointer variable name. For example, fmt.Println(*p) prints the value of the variable pointed to by pointer p.

Finding the Capacity of a Pointer

To find the capacity of a pointer in Golang, we first need to create a data structure and allocate memory to it using the make() function. The make() function returns a pointer to the memory block allocated.

For example, to create a slice with a capacity of 10, we use the following code −

s := make([]int, 0, 10)

Here, make() creates a slice of integers with a length of 0 and a capacity of 10. The returned value is a pointer to the memory block allocated for the slice.

We can find the capacity of the pointer using the cap() function. The cap() function takes a slice or a pointer as an argument and returns the capacity of the underlying memory block.

For example, to find the capacity of pointer p, we can use the following code −

p := make([]int, 0, 10)
fmt.Println(cap(p))

This will print 10, which is the capacity of the memory block pointed to by pointer p.

Conclusion

In conclusion, finding the capacity of a pointer in Golang is a simple task. We can use the make() function to allocate memory for a data structure and get a pointer to the allocated memory. Then, we can use the cap() function to find the capacity of the memory block pointed to by the pointer.

Understanding pointers and their capacity is important for Golang developers who work with large data structures and want to optimize memory usage. With the knowledge gained from this article, you can now easily find the capacity of a pointer in Golang.

Updated on: 05-May-2023

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