What's the Difference Between `=` and `:=` Assignment Operators in Go?

Understanding := and = Operators in Go

In Go programming, the assignment operators "=" and ":=" may appear interchangeable for assigning values to variables. However, these operators have distinct roles and usage scenarios.

= Operator: Assignment

The "=" operator is used exclusively for assignment. It assigns a value to an existing variable:

var a int
a = 10 // Assign the value 10 to the variable 'a'

:= Operator: Declaration and Assignment

In contrast, the ":=" operator combines declaration and assignment. This means it can both create and initialize a new variable at the same time:

b := 10 // Declare and assign the variable 'b' with the value 10

Usage Cases

When to Use =:

• Assigning values to existing variables
• Modifying the value of a declared variable

When to Use :=:

• Declaring and initializing new variables
• Assigning values to variables within the same line of code
• To shorten the declaration and assignment process

Example:

Consider the following code:

var c int = 20
d := 30

fmt.Println(c) // Output: 20
fmt.Println(d) // Output: 30

Here, "=" is used to assign the value 20 to the variable "c," which has already been declared. On the other hand, ":=" is used to both declare and initialize the variable "d" with the value 30.

The above is the detailed content of What's the Difference Between `=` and `:=` Assignment Operators in Go?. For more information, please follow other related articles on the PHP Chinese website!