How to Find Length of Struct in Golang?
Last Updated :
22 Jul, 2024
In programming, data structures are vital in organizing and storing data efficiently. One such data structure in Go, also known as Golang, is the struct. This article will delve into the concept of structure in Golang and explore various methods to find its length.
What is Struct with Example?
A struct in Golang is a user-defined type that allows us to group/combine items of possibly different types into a single type. It’s a way to create a data structure that holds data about something and includes its various properties.
Here’s an example:
Go
package main
import (
"fmt"
)
type Employee struct {
Name string
Age int
Salary float64
}
func main() {
emp := Employee{
Name: "John Doe",
Age: 30,
Salary: 50000.00,
}
fmt.Println(emp)
}
Output{John Doe 30 50000}
In this example, Employee is a struct that has three fields: Name, Age, and Salary. We then create a variable emp of type Employee and print it.
Methods of Finding the Size of the Struct in Golang:
In Golang, the unsafe package provides functions to find the size of variables. We can use the Sizeof function from the unsafe package to find the size of a struct. However, it’s important to note that using the unsafe package may lead to code that is not portable across systems or architectures.
Here’s how you can do it:
Go
package main
import (
"fmt"
"unsafe"
)
type Employee struct {
Name string
Age int
Salary float64
}
func main() {
emp := Employee{
Name: "John Doe",
Age: 30,
Salary: 50000.00,
}
fmt.Printf("Size of Employee struct: %d bytes\n", unsafe.Sizeof(emp))
}
OutputSize of Employee struct: 32 bytes
In this code, we use unsafe.Sizeof(emp) to find the size of the Employee struct. The output will be the size of the Employee struct in bytes.
Please note that the size of the struct is not necessarily the sum of the sizes of its fields. This is due to a concept called “padding”, which aligns the fields to memory boundaries for efficient access.
Remember, while the unsafe package provides a way to find the size of a struct, it should be used sparingly and carefully, as it can lead to non-portable code. Always strive to write code that is safe, readable, and maintainable.
Conclusion
In Golang, struct is a powerful data structure that allows us to group data of different types. Although Golang does not provide a built-in method to find the length of a struct, we can use the unsafe package’s Sizeof function to achieve this. However, it’s crucial to use the unsafe package sparingly and responsibly due to its potential to create non-portable code.
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