C中结构体数组变量的初始化与声明

Question

I am getting an error while trying to compile this code.......tried different IDEs

#include<stdio.h>
#include<stdlib.h>
struct car{
        int price[5];
    }c1;
int main(){
    c1.price[5]={10,20,30,40,50};
}

error:

7 14 D:\CODING\c programs\Struct.c [Error] expected expression before '{' token

Answer 1

This isn't valid C. You can only statically initialize an array at definition time. Something like the following:

int price[5] = {10,20,30,40,50};

Otherwise, you must use subscripts to initialize the array:

c1.price[0] = 10;
c1.price[1] = 20;
c1.price[2] = 30;
c1.price[3] = 40;
c1.price[4] = 50;

Try to read the book 'The C Programming language by Ritchie & Kernighan' to get a feel for the language first.

Answer 2

After this declaration

struct car{
    int price[5];
}c1;

the object c1 with its data member are already created that is defined.

So in this statement

c1.price[5]={10,20,30,40,50};

you are trying to assign a braced list to the non-existent element of the array with the index equal to 5 .

Even if you will write instead

c1.price = {10,20,30,40,50};

nevertheless arrays do not have the assignment operator.

You can initialize the data member price of the object c1 when the object is defined. For example

struct car{
    int price[5];
}c1 = { .price={10,20,30,40,50} };

Otherwise to change values of the data member price you should use a loop as for example

for ( size_t i = 0; i < sizeof( c1.price ) / sizeof( *c1.price ); i++ )
{
    c1.price[i] = ( int )( 10 * ( i + 1 ) );
}