Go [language] data structure pointer Know?

pointer

　　Chapter around the strings, numbers, arrays, slices, map, channel, and the structure and the function pointer assignment of the transmission parameter analysis application

 

String

The string itself is StringHeader structure comprising a pointer to the Data string length, the following

type StringHeader struct {
    Data uintptr
    Len  int
}

Data at the memory address can not be changed, the string and pass parameters only copy assignment value and the Data Len of StringHeader

main Package 

Import "FMT" 

FUNC main () { 
	str: "! the Hello World" = 
	var data String 
	data = str 
	// str copy of the Data Len 
	fmt.Println (data) 
	data = "! Go the Hello" 
	// Modify data generating a new value StringHeader structure in memory and assigned to Data 
	fmt.Println (Data) 
	// STR memory unchanged 
	fmt.Println (STR) 
} 

// the Hello World! 
// Go the Hello! 
// the Hello World!

When the string pointer variable is declared, when an object must be a string variable assignment memory address, the function is passed the parameter copy-only memory address　

 

main Package 

Import "FMT" 


FUNC main () { 
	str: "! the Hello World" = 
	var PTR String * 
	// str error method is a string of non-pointer type 
	// str PTR = 
	// str correctly acquired address is assigned to ptr 
	ptr = & str 

	fmt.Println (ptr) 
	fmt.Println (* ptr) 
} 

// 0xc0000421c0 
// the Hello World!