This example shows you how to return a structure from a function.<\/p>\n
Think of the following when reading this:<\/p>\n
\/**\r\n * File: car_return.c\r\n * Author: Risto Heinsar\r\n * Created: 02.02.2015\r\n * Modified 21.01.2026\r\n *\r\n * Description: Example how to return a copy of a struct from a function\r\n *\/\r\n#include <stdio.h>\r\n#include <stdlib.h>\r\n\r\n#define REG_LEN 10\r\n#define FIELD_LEN 128\r\n\r\nstruct Car\r\n{\r\n char regNum[REG_LEN];\r\n char regCity[FIELD_LEN];\r\n char manufacturer[FIELD_LEN];\r\n char model[FIELD_LEN];\r\n int year;\r\n};\r\n\r\nstruct Car EnterCarData(void);\r\nvoid PrintCarData(struct Car autoMobile);\r\nvoid GetString(char str[], int len);\r\nint GetPositiveInt(void);\r\n\r\nint main(void)\r\n{\r\n \/* Store the returned struct *\/\r\n struct Car machine = EnterCarData();\r\n \r\n PrintCarData(machine);\r\n return EXIT_SUCCESS;\r\n}\r\n\r\n\r\n\/**\r\n * Description: Reads the details of a car into a structure and returns it.\r\n *\r\n * Parameters: none\r\n *\r\n * Return: car structure, details of an automobile.\r\n *\/\r\nstruct Car EnterCarData(void)\r\n{\r\n \/* Declare a temporary struct *\/\r\n struct Car vehicle;\r\n \r\n \/* Populate the members of the struct *\/\r\n printf(\"Enter the registration number of the car\\n\");\r\n GetString(vehicle.regNum, REG_LEN);\r\n \r\n printf(\"Enter the registration city of the car\\n\");\r\n GetString(vehicle.regCity, FIELD_LEN);\r\n \r\n printf(\"Enter the manufacturer of the car\\n\");\r\n GetString(vehicle.manufacturer, FIELD_LEN);\r\n \r\n printf(\"Enter the model number of the car\\n\");\r\n GetString(vehicle.model, FIELD_LEN);\r\n \r\n printf(\"Enter the year of manufacturing\\n\");\r\n vehicle.year = GetPositiveInt();\r\n \r\n return vehicle;\r\n}\r\n\r\n\/**\r\n * Description: Outputs the details of an automobile\r\n *\r\n * Parameters: automobile, car structure with the details of a car\r\n *\r\n * Return: none\r\n *\/\r\nvoid PrintCarData(struct Car autoMobile) \r\n{\r\n printf(\"%s %s %s %s %d\\n\", autoMobile.regNum, \r\n autoMobile.regCity,\r\n autoMobile.manufacturer, \r\n autoMobile.model, \r\n autoMobile.year);\r\n}\r\n\r\n\/**\r\n * Description: Reads a positive int from the keyboard, reprompts if \r\n * input is not positive\r\n *\r\n * Parameters: none\r\n *\r\n * Return: Positive integer from stdin\r\n *\/\r\nint GetPositiveInt(void)\r\n{\r\n char temp[FIELD_LEN];\r\n\r\n while (1)\r\n {\r\n \/* Get value as a string and convert to int *\/\r\n GetString(temp, FIELD_LEN);\r\n int ans = atoi(temp);\r\n \r\n \/* Return if result matches criteria*\/\r\n if (ans > 0)\r\n return ans;\r\n \r\n \/* Reprompt on invalid input *\/\r\n printf(\"Error! Input must be a positive number!\\n\");\r\n }\r\n}\r\n\r\n\/**\r\n * Description: Reads a string from stdin and fixes the newline character\r\n *\r\n * Parameters: str - read string to be stored here\r\n * len - maximum length for str\r\n *\r\n * Return: none\r\n *\/\r\nvoid GetString(char *str, int len)\r\n{\r\n \/* Grab user input *\/\r\n fgets(str, len, stdin);\r\n \r\n \/* Identify the newline (if present) *\/\r\n char *pStr = str;\r\n while (*pStr != '\\n' && *pStr != '\\0')\r\n pStr++;\r\n \r\n \/* Get rid of the trailing newline *\/\r\n *pStr = '\\0';\r\n}\r\n<\/pre>\n <\/p>\n","protected":false},"excerpt":{"rendered":"
This example shows you how to return a structure from a function. Think of the following when reading this: The struct is created locally and return. By creating the struct in a dedicated function, we can easily implement error checking that will always be present. This also works nicely if you need to read multiple … Loe edasi Returning a struct<\/span>