Go static language feature analysis

Go language is a statically typed compiled language with the following characteristics: Type system: based on structured types, including basic types, arrays, slices, structures, interfaces, functions and channel types. Variable type declaration: must be declared explicitly and the type cannot be changed. Expression type return: The compiler checks the expression return type, otherwise an error is reported. Compilation and Interpretation: The compiler compiles the program and checks for type correctness, and the interpreter interprets the intermediate representation into machine code. Type assertion: Use switch statements to check and convert variable types at runtime.

Go static language feature analysis

Go is a statically typed, compiled programming language. This means that before a Go program is compiled, the type system checks whether the types of variables and expressions are compatible.

Type system

Go's type system is based on structured types, including the following basic types:

• Numeric types (int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, float32, float64)
• Boolean type (bool)
• String type (string)
• Array type ([]T)
• Slice type ([]T)
• Structure type (struct)
• Interface type (interface{})
• Function type (func)
• Channel type (chan T)

Variables must be explicitly typed, and their type cannot be changed. The expression must return a value of a specific type, otherwise the compiler will throw an error.

Compiler and Interpreter

Go programs are compiled into machine code by the Go compiler. The compiler is responsible for checking the syntax and type correctness of the program. It also converts the program into an intermediate representation (IR), which is interpreted by the interpreter into machine code.

Practical case

Consider the following Go function:

func Sum(a int, b int) int {
    return a + b
}

The compiler will check the type correctness of the function:

• a and b must be of type int because the Sum function returns type int.
• a b The expression must return type int because the type system requires that functions return type int.

If the types are incompatible, the compiler will report an error:

invalid operation: a + b (mismatched types int and float32)

Type assertion

Type assertion is used to check and convert the type of the variable at runtime. The switch statement can be used to perform type assertions:

switch v := interface{}(x).(type) {
case int:
    fmt.Println("x is an int")
case string:
    fmt.Println("x is a string")
default:
    fmt.Println("x is not an int or a string")
}

If x is of type int, print "x is an int"; If x is of type string, print "x is a string"; otherwise print "x is not an int or a string" .

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