C: union members get spoiled when compiled

Here's C code that prints member information to the console.

#include "learnc0006.h"
#include "stdio.h"
#include "string.h"

union Member {
    char name[20];
    int age;
    int height;

void printMember(union Member data);

int learnc0006() {
    union Member data;

    strcpy(data.name, "Rico Angeloni");
    data.age = 30;
    data.height = 175;

    return 0;

void printMember(union Member data) {
    printf("Name: %s\n", data.name);
    printf("Age: %d\n", data.age);
    printf("Height: %d\n", data.height);


I expected no problem, but it showed a slightly different result, printing out a strange value for the name instead of showing the correct one.

Name: \257
Age: 175
Height: 175


Any good solutions would be much appreciated. Thank!


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1 answer

I think you might confuse the structure with union. In a union, an item shares memory.

This means that when you write to the field of age

your union, you are at the same time overwriting the content height

and name

, which you do not intend to do. The same thing happens when you write to height

where you write the latest. You can notice this pretty well, because at the end age

it is the same value as height

and the first character name

is actually character number 175 (displayed as escaped octal \257


Try using struct

instead union




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