What is the difference between go language variables and pointers?

The difference is: 1. Memory allocation method, variables allocate memory on the stack, pointers allocate memory on the heap; 2. Transfer method, variables transfer a copy of the variable, and pointers transfer the address of the variable; 3. Null pointer, a variable cannot be nil, and a pointer can be nil; 4. Dereferencing a null pointer will cause a runtime error, and dereferencing a variable is legal; 5. Variability, a variable changes its value through an assignment operation , the pointer changes the value through dereference operation; 6. Variables are relatively simple and safe; 7. Variable performance is more efficient, etc.

# Operating system for this tutorial: Windows 10 system, Dell G3 computer.

Variables and pointers in Go language are two different concepts, and they have some obvious differences in usage and functions.

First of all, variables are containers used to store data, and can store various types of data. In the Go language, variables are declared using the keyword var, followed by the variable name and type. For example, you can declare an integer variable x as follows:

var x int

The pointer is used to store the address of the variable. In Go language, you can use the keyword & to get the address of a variable. For example, the address of variable x can be obtained and assigned to the pointer ptr as follows:

ptr := &x

The pointer can access the value of the variable pointed to by the pointer through the dereference operator *. For example, the value of x can be accessed through ptr as follows:

value := *ptr

Next, let’s compare the differences between variables and pointers.

Memory allocation method: Variables allocate memory on the stack, while pointers allocate memory on the heap. Variables are automatically released when the function ends, while pointers need to be released manually.

Transmission method: The transfer of variables is by value, that is, a copy of the variable is transferred. The pointer is passed by reference, that is, the address of the variable is passed.

Null pointer: Variables cannot be nil, but pointers can be nil. When a pointer is nil, it means that it does not point to any valid memory address.

Null pointer dereference: Dereferencing a null pointer will cause a runtime error. It is legal to dereference variables.

Variability: Variables are mutable and their values ​​can be changed through assignment operations. The variable pointed to by the pointer is also mutable, and its value can be changed through dereference operations.

Safety: Since the use of pointers requires manual memory management, you need to be extra careful when using pointers to avoid problems such as memory leaks and dangling pointers. The use of variables is relatively simple and safe.

Performance: Because pointers require additional memory management operations, there may be a certain overhead in performance. The use of variables does not require additional memory management operations, so it may be more efficient in terms of performance.

Variables and pointers have different uses and characteristics in the Go language. Variables are used to store data, while pointers are used to access and modify the value of a variable. When using them, you need to pay attention to the declaration and operation of variables and pointers, as well as their differences in memory allocation, transfer methods, null pointer handling, variability, security and performance.

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