What is the difference between Go's type checking and type inference?

In Go, type checking and type inference are two different concepts.

Type checking is the process of verifying that the types of values used in a program are correct according to the rules of the language. In Go, the compiler performs type checking at compile time, checking that the types of all expressions and statements are compatible with their surrounding context. For example, the compiler will check that the operands of an arithmetic expression have compatible numeric types, or that a function call provides the correct number and type of arguments.

Type inference, on the other hand, is the process of deducing the type of an expression or variable automatically, without the need for explicit type declarations. In Go, the compiler can perform type inference for some expressions and variables, based on their context and usage. For example, if we declare a variable and initialize it with a value, the compiler can infer the variable's type from the type of the value. Here's an example:

func main() {
    x := 42
    fmt.Printf("x has type %T\n", x) // prints "x has type int"
}

In this example, we declare a variable **x** and initialize it with the value **42**. Since **42** is an integer literal, the compiler can infer that **x** has type **int**.

Type inference can help reduce the amount of explicit type declarations needed in a program, making the code more concise and easier to read. However, it is important to use type inference judiciously, to ensure that the code remains clear and maintainable.

In summary, type checking and type inference are two different concepts in Go. Type checking is the process of verifying that the types of values used in a program are correct according to the rules of the language, while type inference is the process of deducing the type of an expression or variable automatically, without the need for explicit type declarations.