When nesting structures, the compiler needs to recognize the struct type you intend to use as a member. This can either be by giving a full declaration of the struct (show in in the example) or by providing a forward declaration only, assuming that a full declaration is provided at a different location.<\/p>\n
\/**\r\n * File: car_return.c\r\n * Author: Risto Heinsar\r\n * Created: 02.02.2015\r\n * Modified 31.01.2025\r\n *\r\n * Description: This is an example code showing creation of a nested struct\r\n *\/\r\n#include <stdio.h>\r\n#include <string.h>\r\n\r\n#define REG_LEN 8\r\n#define FIELD_LEN 32\r\n\r\nstruct Vehicle\r\n{\r\n char make[FIELD_LEN];\r\n char model[FIELD_LEN];\r\n};\r\n\r\nstruct CarRegistryEntry\r\n{\r\n char regNum[REG_LEN];\r\n char regCity[FIELD_LEN];\r\n char owner[FIELD_LEN];\r\n int year;\r\n struct Vehicle car;\r\n};\r\n\r\nvoid PrintCar(struct CarRegistryEntry motor);\r\nvoid PrintCarUsingPtr(struct CarRegistryEntry *car);\r\n\r\nint main(void)\r\n{\r\n struct CarRegistryEntry indestructibleHilux;\r\n strcpy(indestructibleHilux.regNum,\"E473CJN\");\r\n strcpy(indestructibleHilux.regCity,\"London\");\r\n strcpy(indestructibleHilux.owner,\"The Stig\");\r\n indestructibleHilux.year = 1988;\r\n strcpy(indestructibleHilux.car.make,\"Toyota\");\r\n strcpy(indestructibleHilux.car.model,\"Hilux\");\r\n\r\n PrintCar(indestructibleHilux);\r\n PrintCarUsingPtr(&indestructibleHilux);\r\n\r\n return 0;\r\n}\r\n\r\n\/**\r\n * Description: Outputs the details of an automobile using . notation\r\n *\r\n * Parameters: motor, vehicle structure with the details of a car\r\n *\r\n * Return: none\r\n *\/\r\nvoid PrintCar(struct CarRegistryEntry motor)\r\n{\r\n printf(\"%s %s, reg number %s, belongs to %s and is registered in %s\\n\",\r\n motor.car.make, motor.car.model, \r\n motor.regNum, motor.owner, \r\n motor.regCity);\r\n}\r\n\r\n\/**\r\n * Description: Outputs the details of an automobile using -> notation\r\n *\r\n * Parameters: motor, vehicle structure with the details of a car\r\n *\r\n * Return: none\r\n *\/\r\nvoid PrintCarUsingPtr(struct CarRegistryEntry *motor)\r\n{\r\n printf(\"%s %s, reg number %s, belongs to %s and is registered in %s\\n\",\r\n motor->car.make, motor->car.model,\r\n motor->regNum, motor->owner,\r\n motor->regCity);\r\n}\r\n<\/pre>\n <\/p>\n","protected":false},"excerpt":{"rendered":"
When nesting structures, the compiler needs to recognize the struct type you intend to use as a member. This can either be by giving a full declaration of the struct (show in in the example) or by providing a forward declaration only, assuming that a full declaration is provided at a different location. \/** * … Loe edasi Substruct example<\/span>